METHODS AND COMPOSITIONS FOR THE DIAGNOSIS AND TREATMENT OF NEUROPSYCHIATRIC DISORDERS

Abstract: The present invention relates to the mammalian Hcen-2 gene. The invention relates to methods for the identification of compounds that modulate the expression of Hcen-2 and to using such compounds as therapeutic agents in the treatment of Hcen-2 disorders. The invention also relates to methods for the diagnostic evaluation, genetic testing and prognosis of Hcen-2 mediated disorders, and to methods and compositions for the treatment of these disorders. The invention also relates to use of the Hcen-2 gene and/or gene products as markers for fine structure mapping of a region of human chromosome 18, including a region of the chromosome involved in mediating neuropsychiatric disorders.

Description: METHODS AND COMPOSITIONS FOR TEE DIAGNOSIS AND TREATMENT OF NEUROPSYCHIATRIC DISORDERS 1. INTRODUCTION The present invention relates to drug screening assays, and diagnostic and therapeutic methods for the treatment of neuropsychiatric disorders, mediated by the expression of the mutant form of the human centrin (Hcen-2) gene or by aberrant levels of Hcen-2 expression. The invention is based on Applicant's discovery that the Hcen-2 gene is linked to the short arm of chromosome 18 in a region of the chromosome involved in mediating neuropsychiatric disorders such as bipolar-affected disorder (BAD) . Thus, the invention relates to use of the Hcen-2 gene and/or gene products as markers for fine structure mapping of a region of human chromosome 18, including a region of the chromosome involved in mediating neuropsychiatric disorders. The invention also relates to methods for the identification of compounds that modulate the expression, synthesis and activity of the Hcen-2 protein/gene and to using compounds such as those identified as therapeutic agents in the treatment of an Hcen-2 mediated disorder; a neuropsychiatric disorder, including, by way of example and not of limitation, bipolar affective disorder. The invention also relates to methods for the diagnostic evaluation, genetic testing and prognosis of Hcen-2 mediated disorders. 2. BACKGROUND OF THE INVENTION There are only a few psychiatric disorders in which clinical manifestations of the disorder can be correlated with demonstrable defects in the structure and/or function of the nervous system. Well-known examples of such disorders include Huntington's disease, which can be traced to a mutation in a single gene and in which neurons in the εtriatum degenerate, and Parkinson's disease, in which dopaminergic neurons in the nigro-striatal pathway degenerate. The vast majority of psychiatric disorders, however, presumably involve subtle and/or undetectable changes, at the cellular and/or molecular levels, in nervous system structure and function. This lack of detectable neurological defects distinguishes "neuropsychiatric" disorders, such as schizophrenia, attention deficit disorders, schizoaffective disorder, bipolar affective disorders, or unipolar affective disorder, from neurological disorders, in which anatomical or biochemical pathologies are manifest. Hence, identification of the causative defects and the neuropathologies of neuropsychiatric disorders are needed in order to enable clinicians to evaluate and prescribe appropriate courses of treatment to cure or ameliorate the symptoms of these disorders. One of the most prevalent and potentially devastating of neuropsychiatric disorders is bipolar affective disorder (BAD) , also known as bipolar mood disorder (BP) or manic- depressive illness, which is characterized by episodes of elevated mood (mania) and depression (Goodwin, et al . , 1990, Manic Depressive Illness , Oxford University Press, New York) . The most severe and clinically distinctive forms of BAD are BP-I (severe bipolar affective (mood) disorder) , which affects 2-3 million people in the United States, and SAD-M (schizoaffective disorder manic type) . They are characterized by at least one full episode of mania, with or without episodes of major depression (defined by lowered mood, or depression, with associated disturbances in rhythmic behaviors such as sleeping, eating, and sexual activity) . BP-I often co-segregates in families with more etiologically heterogeneous syndromes, such as with a unipolar affective disorder such as unipolar major depressive disorder (MDD) , which is a more broadly defined phenotype (Freimer and Reus, 1992, in The Molecular and Genetic Basis of Neurological Disease , Rosenberg, et al., eds., Butterworths, New York, pp. 951-965; Mclnnes and Freimer, 1995, Curr. Opin. Genet. Develop., 5, 376-381). BP-I and SAD-M are severe mood disorders that are frequently difficult to distinguish from one another on a cross-sectional basis, follow similar clinical courses, and segregate together in family studies (Rosenthal, et al . , 1980, Arch. General Psychiat. 37, 804- 810; Levinson and Levitt, 1987, Am. J. Psychiat. 144, 415- 426; Goodwin, et al . , 1990, Manic Depressive Illness , Oxford University Press, New York) . Hence, methods for distinguishing neuropsychiatric disorders such as these are needed in order to effectively diagnose and treat afflicted individuals. Currently, individuals are typically evaluated for BAD using the criteria set forth in the most current version of the American Psychiatric Association's Diagnostic and Statistical Manual of Mental Disorders (DSM) . While many drugs have been used to treat individuals diagnosed with BAD, including lithium salts, carbamazepine and valproic acid, none of the currently available drugs are adequate. For example, drug treatments are effective in only approximately 60-70% of individuals diagnosed with BP-I. Moreover, it is currently impossible to predict which drug treatments will be effective in, for example, particular BP-I affected individuals. Commonly, upon diagnosis, affected individuals are prescribed one drug after another until one is found to be effective. Early prescription of an effective drug treatment, therefore, is critical for several reasons, including the avoidance of extremely dangerous manic episodes and the risk of progressive deterioration if effective treatments are not found. The existence of a genetic component for BAD is strongly supported by segregation analyses and twin studies (Bertelson, et al . , 1977, Br. J. Psychiat. 130, 330-351; Freimer and Reus, 1992, in The Molecular and Genetic Basis of Neurological Disease , Rosenberg, et al . , eds., Butterworths, New York, pp. 951-965; Pauls, et al . , 1992, Arch. Gen. Psychiat. 49, 703-708). Efforts to identify the chromosomal location of genes that might be involved in BP-I, however, have yielded disappointing results in that reports of linkage between BP-I and markers on chromosomes X and 11 could not be independently replicated nor confirmed in the re-analyses of the original pedigrees, indicating that with BAD linkage studies, even extremely high lod scores at a single locus, can be false positives (Baron, et al . , 1987, Nature 326, 289- 292; Egeland, et al., 1987, Nature 325, 783-787; Kelsoe, et al . , 1989, Nature 342, 238-243; Baron, et al . , 1993, Nature Genet. 3, 49-55) . Recent investigations have suggested possible localization of BAD genes on chromosomes 18p and 21q, but in both cases the proposed candidate region is not well defined and no unequivocal support exists for either location (Berrettini, et al . , 1994, Proc. Natl. Acad. Sci. USA 91, 5918-5921; Murray, et al . , 1994, Science 265, 2049-2054; Pauls, et al . , 1995, Am. J. Hum. Genet. 57, 636-643; Maier, et al., 1995, Psych. Res. 59, 7-15; Straub, et al., 1994, Nature Genet. 8, 291-296). Mapping genes for common diseases believed to be caused by multiple genes, such as BAD, may be complicated by the typically imprecise definition of phenotypes, by etiologic heterogeneity, and by uncertainty about the mode of genetic transmission of the disease trait. With neuropsychiatric disorders there is even greater ambiguity in distinguishing individuals who likely carry an affected genotype from those who are genetically unaffected. For example, one can define an affected phenotype for BAD by including one or more of the broad grouping of diagnostic classifications that constitute the mood disorders: BP-I, SAD-M, MDD, and bipolar affective (mood) disorder with hypomania and major depression (BP-II) . Thus, one of the greatest difficulties facing psychiatric geneticists is uncertainty regarding the validity of phenotype designations, since clinical diagnoses are based solely on clinical observation and subjective reports. Also, with complex traits such as neuropsychiatric disorders, it is difficult to genetically map the trait-causing genes because: (1) neuropsychiatric disorder phenotypes do not exhibit classic Mendelian recessive or dominant inheritance patterns attributable to a single genetic locus, (2) there may be incomplete penetrance, i .e . , individuals who inherit a predisposing allele may not manifest disease; (3) a phenocopy phenomenon may occur, i .e . , individuals who do not inherit a predisposing allele may nevertheless develop disease due to environmental or random causes; (4) genetic heterogeneity may exist, in which case mutations in any one of several genes may result in identical phenotypes. Despite these difficulties, however, identification of the chromosomal location, sequence and function of genes and gene products responsible for causing neuropsychiatric disorders such as bipolar affective disorders is of great importance for genetic counseling, diagnosis and treatment of individuals in affected families. 3. SUMMARY OF THE INVENTION It is an object of the present invention to identify genetic bases for neuropsychiatric disorders, provide methods of treating and diagnosing neuropsychiatric disorders, and provide methods for identifying compounds for use as part of therapeutic and/or diagnostic methods. The invention further relates to methods for the treatment of Hcen-2 mediated neuropsychiatric disorders, wherein such methods comprise administering a compound which modulates the expression of a mammalian Hcen-2 gene and/or the synthesis or activity of a mammalian Hcen-2 gene product so symptoms of the disorder are ameliorated. The invention further relates to methods for the treatment of mammalian Hcen-2 mediated neuropsychiatric disorders resulting from Hcen-2 gene mutations, wherein such methods comprise supplying the mammal with a nucleic acid molecule encoding an unimpaired Hcen-2 gene product such that an unimpaired Hcen-2 gene product is expressed and symptoms of the disorder are ameliorated. The invention further relates to methods for the treatment of mammalian Hcen-2 mediated neuropsychiatric disorders resulting from Hcen-2 gene mutations, wherein such methods comprise supplying the mammal with a cell comprising a nucleic acid molecule that encodes an unimpaired Hcen-2 gene product such that the cell expresses the unimpaired Hcen-2 gene product and symptoms of the disorder are ameliorated. In addition, the present invention is directed to methods that utilize the Hcen-2 gene and/or gene product sequences for the diagnostic evaluation, genetic testing and prognosis of an Hcen-2 mediated disorder. For example, the invention relates to methods for diagnosing Hcen-2 mediated neuropsychiatric disorders, wherein such methods comprise measuring Hcen-2 gene expression in a patient sample, or detecting an Hcen-2 mutation in the genome of the mammal suspected of exhibiting such a disorder. The invention still further relates to methods for identifying compounds capable of modulating the expression of the mammalian Hcen-2 gene and/or the synthesis or activity of the mammalian Hcen-2 gene products, wherein such methods comprise contacting a compound to a cell that expresses an Hcen-2 gene, measuring the level of Hcen-2 gene expression, gene product expression or gene product activity, and comparing this level to the level of Hcen-2 gene expression, gene product expression or gene product activity produced by the cell in the absence of the compound, such that if the level obtained in the presence of the compound differs from that obtained in its absence, a compound capable of modulating the expression of the mammalian Hcen-2 gene and/or the synthesis or activity of the mammalian Hcen-2 gene products has been identified. The invention is based, in part, on the genetic and physical mapping of the Hcen-2 gene to a specific portion of human chromosome 18, and specifically to the short arm of human chromosome 18 between the telomere and D185481, described in the example presented below in Section 6. Thus, the invention also relates to the use of the Hcen-2 gene and/or gene products as markers for fine structure mapping of this region of human. chromosome 18. The term "Hcen-2 mediated disorder" as used herein refers to a disorder involving an aberrant level of Hcen-2 gene expression, gene product synthesis and/or gene product activity relative to levels found in normal, unaffected, unimpaired individuals, levels found in clinically normal individuals, and/or levels found in a population whose level represents a baseline, average Hcen-2 level. 3.1. DEFINITIONS As used herein, the following terms shall have the abbreviations indicated. BAC, bacterial artificial chromosomes BAD, bipolar affective disorder (s) BP, bipolar mood disorder BP-I, severe bipolar affective (mood) disorder BP-II, bipolar affective (mood) disorder with hypomania and major depression bp, base pair(s) EST, expressed sequence tag lod, logarithm of odds MDD, unipolar major depressive disorder ROS, reactive oxygen species RT-PCR, reverse transcriptase PCR SSCP, single-stranded conformational polymorphism SAD-M, schizoaffective disorder manic type STS, short tag sequence YAC, yeast artificial chromosome 4. BRIEF DESCRIPTION OF THE FIGURES FIG. 1. Sequence of the human Hcen-2 gene (SEQ ID NO:l). Amino acid sequences are indicated (SEQ ID NO: 2) . FIGS. 2A-C. Genomic Sequence of the the human Hcen-2 gene (SEQ ID NO: 3). Exons are in bold. The 3' and 5' UTR's are underlined and in bold. 5. DETAILED DESCRIPTION OF THE INVENTION This invention is based on the genetic and physical mapping of the Hcen-2 gene to a specific, narrow portion of chromosome 18, also described in the Example presented below in Section 6. The invention described in the subsections below encompasses screening methods (e.g.. assays) for the identification of compounds which can be used to treat individuals suffering from an Hcen-2 mediated disorder. The invention also encompasses agonists and antagonists of the Hcen-2 gene product, including small molecules, large molecules, and antibodies, as well as nucleotide sequences that can be used to inhibit Hcen-2 gene expression (e.g.. antisense and ribozyme molecules) , and gene or regulatory sequence replacement constructs designed to enhance Hcen-2 gene expression (e.g.. expression constructs that place the Hcen-2 gene under the control of a strong promoter system) . In particular, cellular and non-cellular assays are described that can be used to identify compounds that interact with the Hcen-2 gene product, e.g.. modulate the activity of the Hcen-2 and/or bind to the Hcen-2 gene product. Such cell-based assays of the invention utilize cells, cell lines, or engineered cells or cell lines that express the Hcen-2 gene product. The invention also encompasses the use of cell-based assays or cell-lysate assays (e.g.. in vitro transcription or translation assays) to screen for compounds or compositions that modulate Hcen-2 gene expression. To this end, constructs containing a reporter sequence linked to a regulatory element of the Hcen-2 gene can be used in engineered cells, or in cell lysate extracts, to screen for compounds that modulate the expression of the reporter gene product at the level of transcription. For example, such assays could be used to identify compounds that modulate the expression or activity of transcription factors involved in Hcen-2 gene expression, or to test the activity of triple helix polynucleotides. Alternatively, engineered cells or translation extracts can be used to screen for compounds (including antisense and ribozyme constructs) that modulate the translation of Hcen-2 mRNA transcripts, and therefore, affect expression of the Hcen-2 gene product. The invention also encompasses Hcen-2 gene products, polypeptides (including soluble Hcen-2 polypeptides or peptides) and Hcen-2 fusion proteins for use in non-cell based screening assays, for use in generating antibodies, for diagnostics and therapeutics. Such peptides or polypeptides can be fused to a heterologous protein, e.g.. reporter, an Ig Fc region, etc. , to yield a fusion protein. Such peptides, polypeptides and fusion proteins can be used in the non-cell based assays for screening compounds that interact with, e.g.. modulate the activity of the Hcen-2 gene product and/or bind to the Hcen-2 gene product. Hcen-2 proteins can be used to treat disorders. Such Hcen-2 gene products include but are not limited to soluble derivatives such as peptides or polypeptides corresponding to one or more domains of the Hcen-2 gene product. Alternatively, antibodies to the Hcen-2 protein or anti- idiotypic antibodies that mimic the Hcen-2 gene product (including Fab fragments) , antagonists or agonists can be used to treat neuropsychiatric disorders involving Hcen-2. In yet another approach, nucleotide constructs encoding such Hcen-2 gene products can be used to genetically engineer host cells to express such Hcen-2 gene products jLn vivo; these genetically engineered cells can function as "bioreactors" in the body delivering a continuous supply of Hcen-2 gene product, Hcen-2 peptides, soluble Hcen-2 polypeptides. In addition, this invention presents methods for the diagnostic evaluation and prognosis of Hcen-2 mediated disorders. For example, nucleic acid molecules encoding Hcen-2 can be used as diagnostic hybridization probes or as primers for diagnostic PCR analysis for the identification of Hcen-2 gene mutations, allelic variations and regulatory defects in the Hcen-2 gene. "Gene therapy" approaches for the modulation of Hcen-2 gene expression and/or activity in the treatment of neuropsychiatric disorders are within the scope of the invention. For example, nucleotide constructs encoding functional Hcen-2 gene, mutant Hcen-2 gene, as well as antisense and ribozyme molecules can be used to modulate Hcen-2 gene expression. The invention also encompasses pharmaceutical formulations and methods for treating neuropsychiatric disorders involving the Hcen-2 gene. The present invention presents methods for selecting an effective drug to administer to an individual having an Hcen-2 medicated disorder. Such methods are based on the detection of genetic polymorphisms in the Hcen-2 gene or variations in Hcen-2 gene expression due to altered methylation, differential spinning, or post-transductional modification of the Hcen-2 gene product which can affect the safety and efficacy of a therapeutic agent. 5.1. THE Hcen-2 GENE With respect to Hcen-2 gene sequences as disclosed in Figure 1, such sequences can, for example, be obtained readily by utilizing standard sequencing and bacterial artificial chromosome (BAC) technologies in connection with BAC54 (Identification Reference EpHS996, ATCC Accession No. 98363) . p or example, sheared libraries can be made from BAC54. Fragments of a convenient size, e . g. , in the size range of approximately 1 kb, are cloned into a standard plasmid, and sequenced. Further Hcen-2 sequences can then readily be identified by alignment of the BAC sequences with the Hcen-2 sequences depicted in Figure 1 (SEQ ID NO:l) . Alternatively, BAC subclones containing additional Hcen-2 sequences can be identified by identifying those subclones which hybridize to probes derived from the Hcen-2 sequences depicted in Figure 1. With respect to the cloning of allelic variants of the human Hcen-2 gene and homologues from other species (e.g., mouse) , the isolated Hcen-2 gene sequences disclosed herein may be labeled and used to screen a cDNA library constructed from mRNA obtained from appropriate cells or tissues (e.g., brain tissues) derived from the organism (e.g., mouse) of interest. The hybridization conditions used should be of a lower stringency when the cDNA library is derived from an organism different from the type of organism from which the labeled sequence was derived. Alternatively, the labeled fragment may be used to screen a genomic library derived from the organism of interest, again, using appropriately stringent conditions. Low stringency conditions are well known to those of skill in the art, and will vary predictably depending on the specific organisms from which the library and the labeled sequences are derived. For guidance regarding such conditions see, for example, Sambrook, et al . , 1989, Molecular Cloning, A Laboratory Manual, Second Edition, Cold Spring Harbor Press, N.Y.; and Ausubel, et al . , 1989, Current Protocols in Molecular Biology, Green Publishing Associates and Wiley Interεcience, N.Y. Further, an Hcen-2 gene allelic variant may be isolated from, for example, human nucleic acid, by performing PCR using two degenerate oligonucleotide primer pools designed on the basis of amino acid sequences within the Hcen-2 gene product disclosed herein. The template for the reaction may be cDNA obtained by reverse transcription of mRNA prepared from, for example, human or non-human cell lines or tissue known or suspected to express an Hcen-2 gene allele (such as human leukemia cell lines e . g. , K562 B1A, H630 and H630-1, e .g. Dolnick et al., 1996, Cancer Research 56:1207-3260; Dolnick et al., 1993, Nucleic Acids Res., 21:1747-1752; Black et al., 1996, Cancer Res. 56:700-705). Preferrably, the allelic variant will be isolated from an individual who has an Hcen-2 mediated disorder. The PCR product may be subcloned and sequenced to ensure that the amplified sequences represent the sequences of an Hcen-2 gene nucleic acid sequence. The PCR fragment may then be used to isolate a full length cDNA clone by a variety of methods. For example, the amplified fragment may be labeled and used to screen a bacteriophage cDNA library. Alternatively, the labeled fragment may be used to isolate genomic clones via the screening of a genomic library. PCR technology may also be utilized to isolate full length cDNA sequences. For example, RNA may be isolated, following standard procedures, from an appropriate cellular or tissue source (i.e., one known, or suspected, to express the Hcen-2 gene, such as, for example, brain tissue samples obtained through biopsy or post-mortem) . A reverse transcription reaction may be performed on the RNA using an oligonucleotide primer specific for the most 5 ' end of the amplified fragment for the priming of first strand synthesis. The resulting RNA/DNA hybrid may then be "tailed" with guanines using a standard terminal transferase reaction, the hybrid may be digested with RNAase H, and second strand synthesis may then be primed with a poly-C primer. Thus, cDNA sequences upstream of the amplified fragment may easily be isolated. For a review of cloning strategies that may be used, see e .g. , Sambrook et al . , 1989, supra. As mentioned above, the Hcen-2 gene sequences may be used to isolate mutant Hcen-2 gene alleles, preferably from a human subject. Such mutant alleles may be isolated from individuals either known or proposed to have a genotype that contributes to the symptoms of an Hcen-2 mediated disorder. Mutant alleles and mutant allele products may then be utilized in the therapeutic and diagnostic systems described below. Additionally, such Hcen-2 gene sequences can be used to detect Hcen-2 gene regulatory (e.g., promoter) defects which can be associated with an Hcen-2 mediated neuropsychiatric disorder, a disorder. A cDNA of a mutant allelic variant of the Hcen-2 gene may be isolated, for example, by using PCR, a technique that is well known to those of skill in the art. In this case, the first cDNA strand may be synthesized by hybridizing an oligo-dT oligonucleotide to mRNA isolated from tissue known or suspected to be expressed in an individual putatively carrying the mutant Hcen-2 allele, and by extending the new strand with reverse transcriptase. The second strand of the cDNA is then synthesized using an oligonucleotide that hybridizes specifically to the 5' end of the normal gene. Using these two primers, the product is then amplified via PCR, cloned into a suitable vector, and subjected to DNA sequence analysis through methods well known to those of skill in the art. By comparing the DNA sequence of the mutant Hcen-2 allele to that of the normal Hcen-2 allele, the mutation(s) responsible for the loss or alteration of function of the mutant Hcen-2 gene product can be ascertained. Alternatively, a genomic library can be constructed using DNA obtained from an individual suspected of or known to carry a mutant Hcen-2 allele, or a cDNA library can be constructed using RNA from a tissue known, or suspected, to express a mutant Hcen-2 allele. An unimpaired Hcen-2 gene or any suitable fragment thereof may then be labeled and used as a probe to identify the corresponding mutant Hcen-2 allele in such libraries. Clones containing the mutant Hcen-2 gene sequences may then be purified and subjected to sequence analysis according to methods well known to those of skill in the art. Additionally, an expression library can be constructed utilizing cDNA synthesized from, for example, RNA isolated from a tissue known, or suspected, to express a mutant Hcen-2 allele in an individual suspected of or known to carry such a mutant allele. In this manner, gene products made by the putatively mutant tissue may be expressed and screened using standard antibody screening techniques in conjunction with antibodies raised against the normal Hcen-2 gene product, as described, below, in Section 5.3. (For screening techniques, see, for example, Harlow and Lane, eds., 1988, "Antibodies: A Laboratory Manual", Cold Spring Harbor Press, Cold Spring Harbor.) In cases where an Hcen-2 mutation results in an expressed gene product with altered function (e.g., as a result of a missense or a frameshift mutation) , a polyclonal set of anti-Hcen-2 gene product antibodies are likely to cross-react with the mutant Hcen-2 gene product. Library clones detected via their reaction with such labeled antibodies can be purified and subjected to sequence analysis according to methods well known to those of skill in the art. Hcen-2 mutations can further be detected using PCR amplification techniques. Primers can routinely be designed to amplify overlapping regions of the whole Hcen-2 sequence including the promoter region. In one embodiment, primers are designed to cover the exon-intron boundaries such that, coding regions can be scanned for mutations (see, Figure 2A- C) . Several primers for analysing various Hcen-2 exons are provided in the Examples. Genomic DNA isolated from lymphocytes of normal and affected individuals is used as PCR template. PCR products from normal and affected individuals are compared, either by single strand conformational polymorphism (SSCP) mutation detection techniques and/or by sequencing. The mutations responsible for the loss or alteration of function of the mutant Hcen-2 gene product can then be ascertained. 5.2. PROTEIN PRODUCTS OF THE Hcen-2 GENE Hcen-2 gene products, or peptide fragments thereof, can be prepared for a variety of uses. For example, such gene products, or peptide fragments thereof, can be used for the generation of antibodies, in diagnostic assays, or for the identification of other cellular or extracellular gene products involved in the regulation of Hcen-2 mediated disorders . The amino acid sequence depicted in Figure 1 (SEQ ID NO: 2) represents an Hcen-2 gene product. The Hcen-2 gene product, sometimes referred to herein as an "Hcen-2 protein", includes those gene products encoded by the Hcen-2 gene sequences depicted in Figure 1 (SEQ ID NO:l), as well as other human allelic variants of Hcen-2 that can be identified by the methods herein described. In addition, Hcen-2 gene products may include proteins that represent functionally equivalent gene products. Such an equivalent Hcen-2 gene product may contain deletions, including internal deletions, additions, including additions yielding fusion proteins, or substitutions of amino acid residues within and/or adjacent to the amino acid sequence encoded by the Hcen-2 gene sequences described, above, in Section 5.1, but that result in a "silent" change, in that the change produces a functionally equivalent Hcen-2 gene product. Amino acid substitutions may be made on the basis of similarity in polarity, charge, solubility, hydrophobicity, hydrophilicity, and/or the amphipathic nature of the residues involved. For example, nonpolar (hydrophobic) amino acids include alanine, leucine, isoleucine, valine, proline, phenylalanine, tryptophan, and methionine; polar neutral amino acids include glycine, serine, threonine, cysteine, tyrosine, asparagine, and glutamine; positively charged (basic) amino acids include arginine, lysine, and histidine; and negatively charged (acidic) amino acids include aspartic acid and glutamic acid. Alternatively, where alteration of function is desired, deletion or non-conservative alterations can be engineered to produce altered, including reduced Hcen-2 gene products. Such alterations can, for example, alter one or more of the biological functions of the Hcen-2 gene product. Further, such alterations can be selected so as to generate Hcen-2 gene products that are better suited for expression, scale up, etc. in the host cells chosen. For example, cysteine residues can be deleted or substituted with another amino acid residue in order to eliminate disulfide bridges. The Hcen-2 gene products, peptide fragments thereof and fusion proteins thereof, may be produced by recombinant DNA technology using techniques well known in the art. Thus, methods for preparing the Hcen-2 gene products, polypeptides, peptides, fusion peptide and fusion polypeptides of the invention by expressing nucleic acid containing Hcen-2 gene sequences are described herein. Methods that are well known to those skilled in the art can be used to construct expression vectors containing Hcen-2 gene product coding sequences and appropriate transcriptional and translational control signals. These methods include, for example, in vitro recombinant DNA techniques, synthetic techniques, and in vivo genetic recombination. See, for example, the techniques described in Sambrook, et al . , 1989, supra, and Ausubel, et al . , 1989, supra. Alternatively, RNA capable of encoding Hcen-2 gene product sequences may be chemically synthesized using, for example, synthesizers. See, for example, the techniques described in "Oligonucleotide Synthesis", 1984, Gait, ed., IRL Press, Oxford. A variety of host-expression vector systems may be utilized to express the Hcen-2 gene product coding sequences of the invention. Such host-expression systems represent vehicles by which the coding sequences of interest may be produced and subsequently purified, but also represent cells that may, when transformed or transfected with the appropriate nucleotide coding sequences, exhibit the Hcen-2 gene product of the invention in situ . These include but are not limited to microorganisms such as bacteria (e .g. , E. coli , B . subtilis) transformed with recombinant bacteriophage DNA, plasmid DNA or cosmid DNA expression vectors containing Hcen-2 gene product coding sequences; yeast (e .g. , Saccharomyces , Pichia) transformed with recombinant yeast expression vectors containing the Hcen-2 gene product coding sequences; insect cell systems infected with recombinant virus expression vectors (e.g., baculovirus) containing the Hcen-2 gene product coding sequences; plant cell systems infected with recombinant virus expression vectors (e .g. , cauliflower mosaic virus, CaMV; tobacco mosaic virus, TMV) or transformed with recombinant plasmid expression vectors (e . g. , Ti plasmid) containing Hcen-2 gene product coding sequences; or mammalian cell systems (e .g. , COS, CHO, BHK, 293, 3T3) harboring recombinant expression constructs containing promoters derived from the genome of mammalian cells (e .g. , metallothionein promoter) or from mammalian viruses (e .g. , the adenovirus late promoter; the vaccinia virus 7.5K promoter). In bacterial systems, a number of expression vectors may be advantageously selected depending upon the use intended for the Hcen-2 gene product being expressed. For example, when a large quantity of such a protein is to be produced, for the generation of pharmaceutical compositions of Hcen-2 gene product or for raising antibodies to Hcen-2 gene product, for example, vectors that direct the expression of high levels of fusion protein products that are readily purified may be desirable. Such vectors include, but are not limited, to the E. coli expression vector pUR278 (Ruther et al . , 1983, EMBO J. 2, 1791), in which the Hcen-2 gene product coding sequence may be ligated individually into the vector in frame with the lac Z coding region so that a fusion protein is produced; pIN vectors (Inouye and Inouye, 1985, Nucleic Acids Res. 13, 3101-3109; Van Heeke and Schuster, 1989, J. Biol. Chem. 264, 5503-5509); and the like. pGEX vectors may also be used to express foreign polypeptides as fusion proteins with glutathione S-transferase (GST) . In general, such fusion proteins are soluble and can easily be purified from lysed cells by adsorption to glutathione- agarose beads followed by elution in the presence of free glutathione. The pGEX vectors are designed to include thrombin or factor Xa protease cleavage sites so that the cloned target gene product can be released from the GST moiety. In an insect system, Autographa calif ornica , nuclear polyhedrosis virus (AcNPV) is used as a vector to express foreign genes. The virus grows in Spodoptera frugiperda cells. The Hcen-2 gene product coding sequence may be cloned individually into non-essential regions (for example the polyhedrin gene) of the virus and placed under control of an AcNPV promoter (for example the polyhedrin promoter) . Successful insertion of Hcen-2 gene product coding sequence will result in inactivation of the polyhedrin gene and production of non-occluded recombinant virus (i .e . , virus lacking the proteinaceous coat coded for by the polyhedrin gene) . These recombinant viruses are then used to infect Spodoptera frugiperda cells in which the inserted gene is expressed. (e .g. , see Smith, et al . , 1983, J. Virol. 46, 584; Smith, U.S. Patent No. 4,215,051). In mammalian host cells, a number of viral-based expression systems may be utilized. In cases where an adenovirus is used as an expression vector, the Hcen-2 gene product coding sequence of interest may be ligated to an adenovirus transcription/translation control complex, e .g. , the late promoter and tripartite leader sequence. This chimeric gene may then be inserted in the adenovirus genome by in vitro or in vivo recombination. Insertion in a non- essential region of the viral genome (e .g. , region El or E3) will result in a recombinant virus that is viable and capable of expressing Hcen-2 gene product in infected hosts. (e .g. , See Logan and Shenk, 1984, Proc. Natl. Acad. Sci. USA 81, 3655-3659) . Specific initiation signals may also be required for efficient translation of inserted Hcen-2 gene product coding sequences. These signals include the ATG initiation codon and adjacent sequences. In cases where an entire Hcen- 2 gene, including its own initiation codon and adjacent sequences, is inserted into the appropriate expression vector, no additional translational control signals may be needed. However, in cases where only a portion of the Hcen-2 gene coding sequence is inserted, exogenous translational control signals, including, perhaps, the ATG initiation codon, must be provided. Furthermore, the initiation codon must be in phase with the reading frame of the desired coding sequence to ensure translation of the entire insert. These exogenous translational control signals and initiation codons can be of a variety of origins, both natural and synthetic. The efficiency of expression may be enhanced by the inclusion of appropriate transcription enhancer elements, transcription terminators, etc. (see Bittner, et al . , 1987, Methods in Enzymol. 153, 516-544). In addition, a host cell strain may be chosen that modulates the expression of the inserted sequences, or modifies and processes the gene product in the specific fashion desired. Such modifications (e .g. , glycosylation) and processing (e .g. , cleavage) of protein products may be important for the function of the protein. Different host cells have characteristic and specific mechanisms for the post-translational processing and modification of proteins and gene products. Appropriate cell lines or host systems can be chosen to ensure the correct modification and processing of the foreign protein expressed. To this end, eukaryotic host cells that possess the cellular machinery for proper processing of the primary transcript, glycosylation, and phosphorylation of the gene product may be used. Such mammalian host cells include but are not limited to CHO, VERO, BHK, HeLa, COS, MDCK, 293, 3T3 , and WI38. For long-term, high-yield production of recombinant proteins, stable expression is preferred. For example, cell lines that stably express the Hcen-2 gene product may be engineered. Rather than using expression vectors that contain viral origins of replication, host cells can be transformed with DNA controlled by appropriate expression control elements (e .g. , promoter, enhancer, sequences, transcription terminators, polyadenylation sites, etc.), and a selectable marker. Following the introduction of the foreign DNA, engineered cells may be allowed to grow for 1-2 days in an enriched media, and then are switched to a selective media. The selectable marker in the recombinant plasmid confers resistance to the selection and allows cells to stably integrate the plasmid into their chromosomes and grow to form foci that in turn can be cloned and expanded into cell lines. This method may advantageously be used to engineer cell lines that express the Hcen-2 gene product. Such engineered cell lines may be particularly useful in screening and evaluation of compounds that affect the endogenous activity of the Hcen-2 gene product. A number of selection systems may be used, including but not limited to the herpes simplex virus thymidine kinase (Wigler, et al . , 1977, Cell 11, 223), hypoxanthine-guanine phosphoribosyltransferase (Szybalska and Szybalski, 1962, Proc. Natl. Acad. Sci. USA 48, 2026), and adenine phosphoribosyltransferase (Lowy, et al . , 1980, Cell 22, 817) genes can be employed in tk, hgprt" or aprt" cells, respectively. Also, antimetabolite resistance can be used as the basis of selection for the following genes: dhfr, which confers resistance to methotrexate (Wigler, et al . , 1980, Natl. Acad. Sci. USA 77, 3567; O'Hare, et al . , 1981, Proc. Natl. Acad. Sci. USA 78, 1527); gpt, which confers resistance to mycophenolic acid (Mulligan and Berg, 1981, Proc. Natl. Acad. Sci. USA 78, 2072); neo, which confers resistance to the aminoglycoside G-418 (Colberre-Garapin, et al . , 1981, J. Mol. Biol. 150, 1) ; and hygro, which confers resistance to hygromycin (Santerre, et al . , 1984, Gene 30, 147). Alternatively, any fusion protein may be readily purified by utilizing an antibody specific for the fusion protein being expressed. For example, a system described by Janknecht, et al . allows for the ready purification of nόn- denatured fusion proteins expressed in human cell lines (Janknecht, et al . , 1991, Proc. Natl. Acad. Sci. USA 88, 8972-8976) . In this system, the gene of interest is subcloned into a vaccinia recombination plasmid such that the gene's open reading frame is translationally fused to an amino-terminal tag consisting of six histidine residues. Extracts from cells infected with recombinant vaccinia virus are loaded onto Ni 2+ -nitriloacetic acid-agarose columns and hiεtidine-tagged proteins are selectively eluted with imidazole-containing buffers. The Hcen-2 gene products can also be expressed in transgenic animals. Animals of any species, including, but not limited to, mice, rats, rabbits, guinea pigs, pigs, micro-pigs, goats, sheep, and non-human primates, e .g. , baboons, monkeys, and chimpanzees may be used to generate Hcen-2 transgenic animals. The term "transgenic," as used herein, refers to animals expressing Hcen-2 gene sequences from a different species (e.g., mice expressing human Hcen-2 gene sequences) , as well as animals that have been genetically engineered to overexpress endogenous (i .e . , same species) Hcen-2 sequences or animals that have been genetically engineered to no longer express endogenous Hcen-2 gene sequences (i .e . , "knock-out" animals), and their progeny. Any technique known in the art may be used to introduce an Hcen-2 gene transgene into animals to produce the founder lines of transgenic animals. Such techniques include, but are not limited to pronuclear microinjection (Hoppe and Wagner, 1989, U.S. Pat. No. 4,873,191); retrovirus mediated gene transfer into germ lines (Van der Putten, et al . , 1985, Proc. Natl. Acad. Sci., USA 82, 6148-6152); gene targeting in embryonic stem cells (Thompson, et al . , 1989, Cell 56, 313- 321); electroporation of embryos (Lo, 1983, Mol. Cell. Biol. 3, 1803-1814); and sperm-mediated gene transfer (Lavitrano et al . , 1989, Cell 57, 717-723) (For a review of such techniques, see Gordon, 1989, Transgenic Animals, Intl. Rev. Cytol. 115, 171-229) Any technique known in the art may be used to produce transgenic animal clones containing an Hcen-2 transgene, for example, nuclear transfer into enucleated oocytes of nuclei from cultured embryonic, fetal or adult cells induced to quiescence (Campbell, et al . , 1996, Nature 380, 64-66; Wilmut, et al . , Nature 385, 810-813). The present invention provides for transgenic animals that carry an Hcen-2 transgene in all their cells, as well as animals that carry the transgene in some, but not all their cells, i .e . , mosaic animals. The transgene may be integrated as a single transgene or in concatamerε, e .g. , head-to-head tandems or head-to-tail tandems. The transgene may also be εelectively introduced into and activated in a particular cell type by following, for example, the teaching of Laεko et al . (Laεko, et al., 1992, Proc. Natl. Acad. Sci. USA 89, 6232-6236) . The regulatory sequences required for such a cell-type specific activation will depend upon the particular cell type of interest, and will be apparent to those of skill in the art. When it iε deεired that the Hcen-2 tranεgene be integrated into the chromosomal site of the endogenous Hcen-2 gene, gene targeting is preferred. Briefly, when such a technique is to be utilized, vectors containing some nucleotide εequences homologous to the endogenous Hcen-2 gene are designed for the purpose of integrating, via homologous recombination with chromosomal sequences, into and disrupting the function of the nucleotide sequence of the endogenous Hcen-2 gene. The transgene may also be selectively introduced into a particular cell type, thuε inactivating the endogenouε Hcen-2 gene in only that cell type, by following, for example, the teaching of Gu, et al. (Gu, et al . , 1994, Science 265, 103-106) . The regulatory sequences required for such a cell-type specific inactivation will depend upon the particular cell type of interest, and will be apparent to those of εkill in the art. Once tranεgenic animals have been generated, the expression of the recombinant Hcen-2 gene may be asεayed utilizing εtandard techniques. Initial screening may be accomplished by Southern blot analysis or PCR techniques to analyze animal tisεues to assay whether integration of the transgene has taken place. The level of mRNA expresεion of the tranεgene in the tiεεueε of the transgenic animals may also be assesεed using techniques that include but are not limited to Northern blot analysis of tissue sampleε obtained from the animal, in situ hybridization analyεiε, and RT-PCR (reverεe tranεcriptase PCR) . Samples of Hcen-2 gene- expreεεing tisεue, may alεo be evaluated immunocytochemically using antibodies specific for the Hcen-2 transgene product. 5.3. ANTIBODIES TO Hcen-2 GENE PRODUCTS Described herein are methods for the production of antibodies capable of specifically recognizing one or more Hcen-2 gene product epitopes or epitopes of conserved variants or peptide fragments of the Hcen-2 gene products. Further, antibodies that specifically recognize mutant forms of Hcen-2, are encompasεed by the invention. Such antibodieε may include, but are not limited to, polyclonal antibodieε, monoclonal antibodieε (mAbs) , humanized or chimeric antibodies, single chain antibodies, Fab fragments, F(ab') fragments, fragments produced by a Fab expresεion library, anti-idiotypic (anti-Id) antibodies, and epitope-binding fragments of any of the above. Such antibodies may be used, for example, in the detection of an Hcen-2 gene product in an biological sample and may, therefore, be utilized as part of a diagnoεtic or prognoεtic technique whereby patientε may be tested for abnormal levels of Hcen-2 gene products, and/or for the preεence of abnormal formε of such gene productε. Such antibodieε may also be utilized in conjunction with, for example, compound screening schemes, as described, below, in Section 5.8, for the evaluation of the effect of test compoundε on Hcen-2 gene product levelε and/or activity. Additionally, εuch antibodieε can be uεed in conjunction with the gene therapy techniqueε described, below, in Section 5.9.2 to, for example, evaluate the normal and/or engineered Hcen-2- expressing cells prior to their introduction into the patient. Anti-ffcen-2 gene product antibodies may additionally be used in methods for inhibiting abnormal Hcen-2 gene product activity. Thus, such antibodies may, therefore, be utilized as part of treatment methods for an Hcen-2 mediated diεorder. For the production of antibodieε againεt an Hcen-2 gene product, various host animals may be immunized by injection with an Hcen-2 gene product, or a portion thereof. Such host animals may include, but are not limited to rabbits, mice, and rats, to name but a few. Various adjuvantε may be uεed to increaεe the immunological reεponεe, depending on the hoεt εpecies, including but not limited to Freund's (complete and incomplete) , mineral gels such as aluminum hydroxide, surface active subεtanceε εuch aε lysolecithin, pluronic polyols, polyanions, peptides, oil emulsions, keyhole limpet hemocyanin, dinitrophenol, and potentially useful human adjuvants such as BCG (bacille Calmette-Guerin) and Corynebacterium parvum. Polyclonal antibodies are heterogeneous populations of antibody molecules derived from the sera of animalε immunized with an antigen, such as an Hcen-2 gene product, or an antigenic functional derivative thereof. For the production of polyclonal antibodies, host animals such as those described above, may be immunized by injection with Hcen-2 gene product supplemented with adjuvantε as also described above. Monoclonal antibodies, which are homogeneous populations of antibodies to a particular antigen, may be obtained by any technique that provideε for the production of antibody moleculeε by continuouε cell lines in culture. These include,, but are not limited to, the hybridoma technique of Kohler and Milεtein, (1975, Nature 256, 495-497; and U.S. Patent No. 4,376,110), the human B-cell hybridoma technique (Koεbor et al . , 1983, Immunology Today 4, 72; Cole et al . , 1983, Proc. Natl. Acad. Sci. USA 80, 2026-2030), and the EBV- hybridoma technique (Cole et al . , 1985, Monoclonal Antibodieε And Cancer Therapy, Alan R. Liεε, Inc., pp. 77-96). Such antibodieε may be of any immunoglobulin class including IgG, IgM, IgE, IgA, IgD and any subclaεε thereof. The hybridoma producing the mAb of this invention may be cultivated in vitro or in vivo . Production of high.titerε of mAbε in vivo makes this the presently preferred method of production. In addition, techniques developed for the production of "chimeric antibodies" (Morrison, et al . , 1984, Proc. Natl. Acad. Sci., 81, 6851-6855; Neuberger, et al . , 1984, Nature 312, 604-608; Takeda, et al . , 1985, Nature, 314, 452-454) by εplicing the geneε from a mouse antibody molecule of appropriate antigen specificity together with genes from a human antibody molecule of appropriate biological activity can be uεed. A chimeric antibody iε a molecule in which different portions are derived from different animal specieε, such as those having a variable region derived from a murine mAb and a human immunoglobulin constant region. (See, e .g. , Cabilly et al., U.S. Patent No. 4,816,567; and Bosε et al. , U.S. Patent No. 4,816397, which are incorporated herein by reference in their entirety.) In addition, techniqueε have been developed for the production of humanized antibodieε. (See, e .g. , Queen, U.S. Patent No. 5,585,089, which iε incorporated herein by reference in itε entirety.) An immunoglobulin light or heavy chain variable region consists of a "framework" region interrupted by three hypervariable regions, referred to as complementarily determining regions (CDRs) . The extent of the framework region and CDRs have been preciεely defined (see, "Sequences of Proteins of Immunological Interest", Kabat, E. et al., U.S.Department of Health and Human Services (1983) . Briefly, humanized antibodies are antibody molecules from non-human species having one or more CDRε from the non- human εpecieε and a framework region from a human immunoglobulin molecule. Alternatively, techniques described for the production of single chain antibodies (U.S. Patent 4,946,778; Bird, 1988, Science 242, 423-426; Huston, et al . , 1988, Proc. Natl. Acad. Sci. USA 85, 5879-5883; and Ward, et al . , 1989, Nature 334, 544-546) can be adapted to produce single chain antibodieε againεt Hcen-2 gene products. Single chain antibodies are formed by linking the heavy and light chain fragmentε of the Fv region via an amino acid bridge, reεulting in a εingle chain polypeptide. Antibody fragmentε that recognize εpecific epitopeε may be generated by known techniques. For example, such fragments include but are not limited to: the F(ab') 2 fragments, which can be produced by pepsin digestion of the antibody molecule and the Fab fragments, which can be generated by reducing the disulfide bridgeε of the F(ab') 2 fragmentε. Alternatively, Fab expreεεion librarieε may be conεtructed (Huεe, et al . , 1989, Science, 246, 1275-1281) to allow rapid and easy identification of monoclonal Fab fragments with the desired specificity. 5.4. USES OF Hcen-2 GENE SEQUENCES GENE PRODUCTS. AND ANTIBODIES Described herein are variouε applicationε of Hcen-2 gene sequences, Hcen-2 gene products, including peptide fragments and fusion proteins thereof, and of antibodies directed against Hcen-2 gene products and peptide fragments thereof. Such applications include, for example, prognostic and diagnostic evaluation of an Hcen-2 mediated disorder BAD, and the identification of subjects with a prediεpoεition to εuch disorders, as described, below, in Section 5.5. Additionally, such applications include methods for the treatment of an Hcen-2 mediated disorder aε deεcribed, below, in Section 5.9, and for the identification of compoundε that modulate the expreεεion of the Hcen-2 gene and/or the εyntheεiε or activity of the Hcen-2 gene product, aε described below, in Section 5.8. Such compounds can include, for example, other cellular productε that are involved in Hcen-2 mediated diεorderε. Theεe compoundε can be uεed, for example, in the amelioration of Hcen-2 mediated diεorderε. 5.5. DIAGNOSIS OF ABNORMALITIES OF AN Hcen-2, MEDIATED DISORDER A variety of methodε can be employed for the diagnostic and prognostic evaluation of Hcen-2 mediated disorderε and for the identification of εubjectε having a prediεposition to such disorderε. Such methodε may, for example, utilize reagents such as the Hcen-2 gene nucleotide εequenceε described in Sections 5.1, and antibodieε directed againεt Hcen-2 gene productε, including peptide fragmentε thereof, aε deεcribed, above, in Section 5.3. Specifically, such reagents may be uεed, for example, for: (1) the detection of the presence of Hcen-2 gene mutations, or the detection of either over- or under- expreεεion of Hcen-2 protein; (2) the detection of over- or under-abundance of Hcen-2 gene product; and (3) the detection of an aberrant level of Hcen-2 gene product activity. Hcen-2 gene nucleotide sequences can, for example, be used to diagnose an Hcen-2 mediated disorder using, for example, the techniques for Hcen-2 mutation detection described above in Section 5.1. Mutations at a number of different genetic loci may lead to phenotypes related to Hcen-2 mediated diεorderε. Ideally, the treatment of patientε εuffering from εuch an Hcen-2 mediated disorder will be designed to target the particular genetic loci containing the mutation mediating the disorder. Genetic polymorphisms have been linked to differences in drug effectiveness. Thus, identification of alterationε in the Hcen-2 gene or protein can be utilized to optimize therapeutic drug treatmentε. In an embodiment of the present invention, polymorphisms in the Hcen-2 gene sequence, or variations in Hcen-2 gene expreεsion due to altered methylation, differential εplicing, or poεt-tranεlational modification of the Hcen-2 gene product, may be utilized to identify an individual having a diseaεe or condition reεulting from an Hcen-2 mediated disorder and thuε define the oεt effective and safeεt drug treatment. Aεεayε such as those deεcribed herein may be used to identify εuch polymorphisms or variations in Hcen-2 gene expreεsion activity. Once a polymorphiεm in the Hcen-2 gene, or a variation in Hcen-2 gene expreεsion has been identified in an individual, an appropriate drug treatment can be prescribed to the individual. The methods described herein may be performed, for example, by utilizing pre-packaged diagnostic kits comprising at least one specific Hcen-2 gene nucleic acid or anti-Hcen-2 gene product antibody reagent described herein, which may be conveniently used, e . g. , in clinical settings, to diagnose patients exhibiting abnormalitieε of an Hcen-2 mediated diεorder. For the detection of Hcen-2 gene mutationε, any nucleated cell can be used as a starting source for genomic nucleic acid. For the detection of Hcen-2 gene expression or Hcen-2 gene products, any cell type or tisεue in which the Hcen-2 gene iε expressed may be utilized. Nucleic acid-based detection techniques are described, below, in Section 5.6. Peptide detection techniques are described, below, in Section 5.7. 5.6. DETECTION OF Hcen-2 NUCLEIC ACID MOLECULES A variety of methods can be employed to screen for the presence of Hcen-2 gene-specific mutations and to detect and/or aεεay levelε of Hcen-2 nucleic acid sequences. Mutations within the Hcen-2 gene can be detected by utilizing a number of techniques. Nucleic acid from any nucleated cell can be uεed as the starting point for εuch aεεay techniqueε, and may be isolated according to standard nucleic acid preparation procedures that are well known to those of skill in the art. Hcen-2 nucleic acid εequenceε may be uεed in hybridization or amplification aεεayε of biological εampleε to detect abnormalities involving Hcen-2 gene structure, including point mutations, insertionε, deletionε, inversionε, tranεlocations and chromosomal rearrangements. Such assayε may include, but are not limited to, Southern analyεes, single-stranded conformational polymorphism analyseε (SSCP) , and PCR analyεes. Diagnostic methods for the detection of Hcen-2 gene- specific mutations can involve for example, contacting and incubating nucleic acidε including recombinant DNA moleculeε, cloned geneε or degenerate variants thereof, obtained from a sample, e .g. , derived from a patient εample or other appropriate cellular source, such as lymphocytes, with one or more labeled nucleic acid reagents including recombinant DNA molecules, cloned geneε or degenerate variantε thereof, aε deεcribed in Section 5.1, under conditionε favorable for the εpecific annealing of theεe reagents to their complementary εequenceε within the Hcen-2 gene. The diagnoεtic methodε of the preεent invention further encompaεε contacting and incubating nucleic acidε for the detection of single nucleotide mutationε or polymorphiεmε of the Hcen-2 gene. Preferably, the lengthε of theεe nucleic acid reagentε are at leaεt 15 to 30 nucleotides. After incubation, all non- annealed nucleic acidε are removed from the nucleic acid: Hcen-2 molecule hybrid. The presence of nucleic acidε that have hybridized, if any εuch molecules exist, is then detected. Using such a detection scheme, the nucleic acid from the cell type or tissue of interest can be immobilized, for example, to a solid support such as a membrane, or a plastic surface such as that on a microtiter plate or polystyrene beadε. In this case, after incubation, non- annealed, labeled nucleic acid reagents of the type described in Section 5.1 are easily removed. Detection of the remaining, annealed, labeled Hcen-2 nucleic acid reagentε iε accomplished using standard techniques well-known to thoεe in the art. The Hcen-2 gene εequences to which the nucleic acid reagents have annealed can be compared to the annealing pattern expected from a normal Hcen-2 gene sequence in order to determine whether an Hcen-2 gene mutation is present. In a preferred embodiment, Hcen-2 mutations or polymorphiεms can be detected by using a microaεεay of Hcen-2 nucleic acid εequenceε immobilized to a εubεtrate or "gene chip" (see, e.g. Cronin, et al. , 1996, Human Mutation 7:244- 255) . Alternative diagnostic methods for the detection of Hcen-2 gene specific nucleic acid molecules, in patient samples or other appropriate cell sourceε, may involve their amplification, e .g. , by PCR (the experimental embodiment set forth in Mulliε, 1987, U.S. Patent No. 4,683,202), followed by the detection of the amplified moleculeε using techniqueε well known to thoεe of εkill in the art. The reεulting amplified εequences can be compared to those that would be expected if the nucleic acid being amplified contained only normal copies of the Hcen-2 gene in order to determine whether an Hcen-2 gene mutation exists. Additionally, well-known genotyping techniques can be performed to identify individuals carrying Hcen-2 gene mutations. Such techniques include, for example, the use of restriction fragment length polymorphisms (RFLPs) , which involve sequence variations in one of the recognition sites for the specific restriction enzyme used. Additionally, improved methods for analyzing DNA polymorphismε, which can be utilized for the identification of Hcen-2 gene-εpecific mutationε, have been deεcribed that capitalize on the presence of variable numbers of short, tandemly repeated DNA sequences between the restriction enzyme εiteε. For example, Weber (U.S. Pat. No. 5,075,217) describes a DNA marker based on length polymorphiεmε in blockε of (dC-dA)n-(dG-dT)n εhort tandem repeats. The average separation of (dC-dA)n-(dG-dT)n blocks is eεtimated to be 30,000-60,000 bp. Markerε that are so cloεely spaced exhibit a high frequency co-inheritance, and are extremely uεeful in the identification of genetic mutationε, such aε, for example, mutationε within the Hcen-2 gene, and the diagnosis of diseaεeε and diεorders related to Hcen-2 mutations. Alεo, Caεkey et al . (U.S. Pat.No. 5,364,759) deεcribe a DNA profiling aεεay for detecting short tri and tetra nucleotide repeat sequenceε. The proceεs includes extracting the DNA of interest, εuch aε the Hcen-2 gene, amplifying the extracted DNA, and labelling the repeat εequences to form a genotypic map of the individual's DNA. The level of Hcen-2 gene expreεεion can alεo be assayed. For example, RNA from a cell type or tissue known, or suspected, to expresε the Hcen-2 gene, εuch aε brain, may be iεolated and teεted utilizing hybridization or PCR techniqueε εuch as are described, above. The iεolated cells can be derived from cell culture or from a patient. The analysiε of cellε taken from culture may be a neceεεary εtep in the asseεεment of cells to be uεed aε part of a cell-baεed gene therapy technique or, alternatively, to teεt the effect of compoundε on the expreεεion of the Hcen-2 gene. Such analyεeε may reveal both quantitative and qualitative aεpectε of the expreεεion pattern of the Hcen-2 gene, including activation or inactivation of Hcen-2 gene expression. In one embodiment of such a detection scheme, a cDNA molecule is syntheεized from an RNA molecule of intereεt (e .g. , by reverεe transcription of the RNA molecule into cDNA) . A sequence within the cDNA is then used as the template for a nucleic acid amplification reaction, such as a PCR amplification reaction, or the like. The nucleic acid reagentε uεed aε synthesis initiation reagents (e .g. , primers) in the reverse transcription and nucleic acid amplification steps of this method are chosen from among the Hcen-2 gene nucleic acid reagentε described in Section 5.1. The preferred lengths of εuch nucleic acid reagentε are at leaεt 9-30 nucleotideε. For detection of the amplified product, the nucleic acid amplification may be performed uεing radioactively or non-radioactively labeled nucleotideε. Alternatively, enough amplified product may be made εuch that the product may be visualized by εtandard ethidium bromide staining or by utilizing any other suitable nucleic acid staining method. Additionally, it is possible to perform such Hcen-2 gene expreεsion assays "in situ", i.e., directly upon tiεsue sections (fixed and/or frozen) of patient tissue obtained from biopsies or resectionε, εuch that no nucleic acid purification iε neceεsary. Nucleic acid reagents εuch aε thoεe deεcribed in Section 5.1 may be uεed aε probeε and/or primerε for εuch in εitu procedures (see, for example, Nuovo, G.J. , 1992, "PCR In Situ Hybridization: Protocols And Applications", Raven Press, NY). Alternatively, if a sufficient quantity of the appropriate cells can be obtained, standard Northern analysis can be performed to determine the level of mRNA expresεion of the Hcen-2 gene. 5.7. DETECTION OF Hcen-2 GENE PRODUCTS Antibodieε directed againεt unimpaired or mutant Hcen-2 gene productε or conεerved variantε or peptide fragments thereof, which are discussed, above, in Section 5.3, may also be used as diagnosticε and prognoεticε for an Hcen-2 mediated disorder. Such methods may be used to detect abnormalities in the level of Hcen-2 gene product synthesis or expresεion, or abnormalities in the structure, temporal expreεεion, and/or phyεical location of Hcen-2 gene product. The antibodieε and immunoaεεay methodε described herein have, for example, important in vitro applicationε in aεεessing the efficacy of treatments for Hcen-2 mediated disorderε. Antibodieε, or fragmentε of antibodieε, εuch aε thoεe deεcribed below, may be uεed to screen potentially therapeutic compounds in vitro to determine their effects on Hcen-2 gene expreεsion and Hcen-2 gene product production. The compounds that have beneficial effectε on an Hcen-2 mediated diεorder. In vitro immunoassayε may alεo be uεed, for example, to assess the efficacy of cell-based gene therapy for an Hcen-2 mediated disorder. Antibodieε directed againεt Hcen-2 gene productε may be uεed in vitro to determine, for example, the level of Hcen-2 gene expreεεion achieved in cellε genetically engineered to produce Hcen-2 gene product. In the caεe of intracellular Hcen-2 gene productε, εuch an aεεeεεment iε done, preferably, using cell lysateε or extractε. Such analyεis will allow for a determination of the number of transformed cells necesεary to achieve therapeutic efficacy in vivo , aε well aε optimization of the gene replacement protocol. The tiεsue or cell type to be analyzed will generally include those that are known, or suεpected, to expreεε the Hcen-2 gene. The protein iεolation methodε employed herein may, for example, be such as those described in Harlow and Lane (1988, "Antibodies: A Laboratory Manual", Cold Spring Harbor Laboratory Presε, Cold Spring Harbor, New York) . The iεolated cellε can be derived from cell culture or from a patient. The analysiε of cells taken from culture may be a necessary step in the aεεessment of cells to be used as part of a cell-based gene therapy technique or, alternatively, to test the effect of compounds on the expresεion of the Hcen-2 gene. Preferred diagnoεtic methodε for the detection of Hcen-2 gene productε, conεerved variantε or peptide fragmentε thereof, may involve, for example, immunoaεεayε wherein the Hcen-2 gene productε or conεerved variantε or peptide fragmentε are detected by their interaction with an anti- Hcen-2 gene product-εpecific antibody. For example, antibodies, or fragments of antibodies, such as those deεcribed, above, in Section 5.3, may be uεed to quantitatively or qualitatively detect the preεence of Hcen-2 gene productε or conεerved variantε or peptide fragmentε thereof. This can be accomplished, for example, by immunofluorescence techniques employing a fluorescently labeled antibody (εee below, thiε Section) coupled with light microscopic, flow cytometric, or fluori etric detection. Such techniques are especially preferred for Hcen-2 gene products that are expreεεed on the cell εurface. The antibodieε (or fragmentε thereof) uεeful in the preεent invention may, additionally, be employed hiεtologically, as in immunofluorescence or immunoeleσtron microscopy, for in situ detection of Hcen-2 gene products, conserved variantε or peptide fragmentε thereof. In εitu detection may be accompliεhed by removing a hiεtological specimen from a patient, and applying thereto a labeled antibody that bindε to an rTε polypeptide. The antibody (or fragment) iε preferably applied by overlaying the labeled antibody (or fragment) onto a biological εample. Through the uεe of εuch a procedure, it iε poεεible to determine not only the preεence of the Hcen-2 gene product, conserved variants or peptide fragments, but also its diεtribution in the examined tiεεue. Uεing the preεent invention, thoεe of ordinary εkill will readily recognize that any of a wide variety of hiεtological methods (such as staining procedures) can be modified in order to achieve in situ detection of an Hcen-2 gene product. Immunoasεayε for Hcen-2 gene productε, conεerved variantε, or peptide fragmentε thereof will typically comprise incubating a εample, εuch as a biological fluid, a tissue extract, freshly harvested cells, or lysates of cells in the presence of a detectably labeled antibody capable of identifying Hcen-2 gene product, conserved variants or peptide fragments thereof, and detecting the bound antibody by any of a number of techniqueε well-known in the art. The biological sample may be brought in contact with and immobilized onto a solid phaεe εupport or carrier, εuch aε nitrocelluloεe, that iε capable of immobilizing cells, cell particles or εoluble proteins. The support may then be washed with suitable buffers followed by treatment with the detectably labeled Hcen-2 gene product specific antibody. The εolid phaεe εupport may then be waεhed with the buffer a second time to remove unbound antibody. The amount of bound label on the solid support may then be detected by conventional means. By "εolid phaεe εupport or carrier" is intended any support capable of binding an antigen or an antibody. Well- known εupportε or carrierε include glaεε, polyεtyrene, polypropylene, polyethylene, dextran, nylon, amylaεeε, natural and modified celluloses, polyacrylamides, gabbros, and magnetite. The nature of the carrier can be either εoluble to εome extent or inεoluble for the purpoεeε of the preεent invention. The support material may have virtually any posεible εtructural configuration so long aε the coupled molecule is capable of binding to an antigen or antibody. Thus, the support configuration may be spherical, as in a bead, or cylindrical, as in the inside εurface of a teεt tube, or the external εurface of a rod. Alternatively, the εurface may be flat εuch as a sheet, test strip, etc. Preferred supports include polystyrene beads. Those skilled in the art will know many other suitable carriers for binding antibody or antigen, or will be able to aεcertain the εame by use of routine experimentation. One of the wayε in which the Hcen-2 gene product- specific antibody can be detectably labeled iε by linking the 5 same to an enzyme, εuch aε for uεe in an enzyme immunoaεεay (EIA) (Voller, A., "The Enzyme Linked Immunosorbent Assay (ELISA)", 1978, Diagnostic Horizons 2, 1-7, Microbiological Associates Quarterly Publication, Walkersville, MD) ; Voller, A. et al . , 1978, J. Clin. Pathol. 31, 507-520; Butler, J.E., 10 1981, Meth. Enzymol. 73, 482-523; Maggio, E. (ed.), 1980, Enzyme Immunoaεsay, CRC Press, Boca Raton, FL, ; Ishikawa, E. et al . , (eds.), 1981, Enzyme Immunoasεay, Kgaku Shoin, Tokyo) . The enzyme which is bound to the antibody will react with an appropriate substrate, preferably a chromogenic 15 substrate, in such a manner as to produce a chemical moiety that can be detected, for example, by spectrophotometric, fluorimetric or by viεual meanε. Enzymeε that can be uεed to detectably label the antibody include, but are not limited to, malate dehydrogenaεe, εtaphylococcal nucleaεe, delta-5- 20 steroid iεomeraεe, yeaεt alcohol dehydrogenaεe, α- glycerophoεphate, dehydrogenase, triose phoεphate iεomerase, horseradish peroxidase, alkaline phosphataεe, aεparaginaεe, glucoεe oxidaεe, /S-galactoεidase, ribonuclease, urease, catalase, glucose-6-phosphate dehydrogenaεe, glucoamylaεe and 25 acetylcholineεteraεe. The detection can be accompliεhed by colori etric methodε that employ a chromogenic εubεtrate for the enzyme. Detection may also be accomplished by viεual comparison of the extent of enzymatic reaction of a substrate in comparison with similarly prepared standardε. 30 Detection may alεo be accompliεhed uεing any of a variety of other immunoassay . For example, by radioactively labeling the antibodieε or antibody fragmentε, it iε poεεible to detect Hcen-2 gene products through the use of a radioimmunoasεay (RIA) (see, for example, Weintraub, B., 35 Principles of Radioimmunoaεεays, Seventh Training Courεe on Radioligand Aεεay Techniques, The Endocrine Society, March, 1986) . The radioactive isotope can be detected by εuch meanε aε the use of a gamma counter or a scintillation counter or by autoradiography. It iε also posεible to label the antibody with a fluorescent compound. When the fluorescently labeled antibody is exposed to light of the proper wave length, its presence can then be detected due to fluorescence. Among the most commonly used fluorescent labeling compounds are fluorescein iεothiocyanate, rhodamine, phycoerythrin, phycocyanin, allophycocyanin, o-phthaldehyde and fluorescamine. The antibody can also be detectably labeled using fluorescence emitting metals such as ,52 Eu, or otherε of the lanthanide series. These metals can be attached to the antibody using εuch metal chelating groupε aε diethylenetriaminepentacetic acid (DTPA) or ethylenediaminetetraacetic acid (EDTA) . The antibody alεo can be detectably labeled by coupling it to a chemilumineεcent compound. The preεence of the chemiluminescent-tagged antibody is then determined by detecting the presence of luminescence that arises during the courεe of a chemical reaction. Examples of particularly useful chemiluminescent labeling compounds are luminol, iεoluminol, theromatic acridinium eεter, imidazole, acridinium εalt and oxalate ester. Likewise, a biolumineεcent compound may be uεed to label the antibody of the preεent invention. Biolumineεcence iε a type of chemiluminescence found in biological syεtemε in which a catalytic protein increaεes the efficiency of the chemiluminescent reaction. The presence of a bioluminescent protein iε determined by detecting the preεence of lumineεcence. Important bioluminescent compounds for purposeε of labeling are luciferin, luciferaεe and aequorin. 5.8. SCREENING ASSAYS FOR COMPOUNDS THAT MODULATE Hcen-2 GENE ACTIVITY The following aεεays are designed to identify compounds that bind to an Hcen-2 gene product, compoundε that bind to intracellular proteins, or portionε of proteins that interact with an Hcen-2 gene product, compounds that interfere with the interaction of an Hcen-2 gene product with intracellular proteins and compounds that modulate the activity of the Hcen-2 gene (i .e . , modulate the level of Hcen-2 gene expression and/or modulate the level of Hcen-2 gene product activity) . Assayε may additionally be utilized that identify compoundε that bind to Hcen-2 gene regulatory εequenceε (e .g. , promoter εequenceε; εee e .g. , Platt, 1994, J. Biol. Chem. 269, 28558-28562), and that can modulate the level of Hcen-2 gene expression. Such compounds may include, but are not limited to, small organic moleculeε, εuch aε ones that are able to croεs the blood-brain barrier, gain entry into an appropriate cell and affect expression of the Hcen-2 gene or some other gene involved in an Hcen-2 regulatory pathway, or intracellular proteinε. Methodε for the identification of εuch intracellular proteinε are deεcribed, below, in Section 5.8.2. Such intracellular proteinε may be involved in the control and/or regulation of mood. Further, among theεe compoundε are compoundε that affect the level of Hcen-2 gene expreεεion and/or Hcen-2 gene product activity and that can be uεed in the therapeutic treatment of Hcen-2 mediated diεorderε aε deεcribed, below, in Section 5.9. Compoundε may include, but are not limited to, peptideε such as, for example, εoluble peptideε, including but not limited to, Ig-tailed fuεion peptideε, and memberε of random peptide librarieε; (εee, e.g., Lam, et al . , 1991, Nature 354, 82-84; Houghten, et al . , 1991, Nature 354, 84-86), and combinatorial chemistry-derived molecular library made of D- and/or L- configuration amino acids, phoεphopeptideε (including, but not limited to memberε of random or partially degenerate, directed phoεphopeptide libraries; see, e .g. , Songyang, et al . , 1993, Cell 72, 767-778), antibodies (including, but not limited to, polyclonal, monoclonal, humanized, anti-idiotypic, chimeric or single chain antibodies, and FAb, F(ab') 2 and FAb expreεεion library fragments, and epitope-binding fragments thereof) , and small organic or inorganic molecules. Such compoundε may further compriεe compoundε, in particular drugs or members of classes or families of drugs, known to ameliorate or exacerbate the symptoms of an Hσen-2 mediated disorder. Such compounds include antidepresεantε such as lithium saltε, carbamazepine, valproic acid, lyεergic acid diethylamide (LSD) , p-chlorophenylalanine, p- propyldopacetamide dithiocarbamate derivatives e .g. , FLA 63; anti-anxiety drugs, e .g. , diazepam; monoamine oxidase (MAO) inhibitorε, e.g., iproniazid, clorgyline, phenelzine and isocarboxazid; biogenic amine uptake blockerε, e .g. , tricyclic antidepressants such aε deεipramine, imipramine and amitriptyline; εerotonin reuptake inhibitorε e.g., fluoxetine; antipεychotic drugε εuch aε phenothiazine derivativeε (e .g. , chlorpromazine (thorazine) and trifluopromazine) ) , butyrophenoneε (e.g., haloperidol (Haldol) ) , thioxanthene derivatives (e .g. , chlorprothixene) , and dibenzodiazepines (e .g. , clozapine) ; benzodiazepines; dopaminergic agoniεtε and antagoniεtε e .g. , L-DOPA, cocaine, amphetamine, α-methy1-tyrosine, reserpine, tetrabenazine, benzotropine, pargyline; noradrenergic agoniεtε and antagoniεtε e.g., clonidine, phenoxybenzamine, phentolamine, tropolone. Compounds identified via assays such aε those described herein may be useful, for example, in elaborating the biological function of the Hcen-2 gene product and for ameliorating Hcen-2 mediated disorderε. Aεεays for testing the effectivenesε of compounds identified by, for example, 0 techniques such as those described in Sectionε 5.8.1 - 5.8.3, are discusεed, below, in Section 5.8.4. 5.8.1. IN VITRO SCREENING ASSAYS FOR COMPOUNDS THAT BIND TO THE Hcen-2 GENE PRODUCT _ In vitro εyεtemε may be deεigned to identify compoundε capable of binding the Hcen-2 gene productε of the invention. Compoundε identified may be uεeful, for example, in modulating the activity of unimpaired and/or mutant Hcen-2 gene products, may be useful in elaborating the biological function of the Hcen-2 gene product, may be utilized in screens for identifying compounds that disrupt normal Hcen-2 gene product interactions, or may in themselves disrupt such interactions. The principle of the assays used to identify compoundε that bind to the Hcen-2 gene product involveε preparing a reaction mixture of the Hcen-2 gene product and the teεt compound under conditionε and for a time sufficient to allow the two components to interact and bind, thus forming a complex that can be removed and/or detected in the reaction mixture. Theεe assayε can be conducted in a variety of ways. For example, one method to conduct such an assay involves anchoring an Hcen-2 gene product or a teεt substance onto a solid support and detecting Hcen-2 gene product/test compound complexeε formed on the solid support at the end of the reaction. In one embodiment of such a method, the Hcen-2 gene product may be anchored onto a solid εupport, and the test compound, which is not anchored, may be labeled, either directly or indirectly. In practice, microtiter plates are conveniently utilized aε the εolid εupport. The anchored component may be immobilized by non-covalent or covalent attachmentε. Non- covalent attachment may be accomplished by simply coating the solid surface with a solution of the protein and drying. Alternatively, an immobilized antibody, preferably a monoclonal antibody, specific for the protein to be immobilized may be used to anchor the protein to the solid surface. The εurfaceε may be prepared in advance and εtored. In order to conduct the aεsay, the non-immobilized component is added to the coated surface containing the anchored component. After the reaction is complete, unreacted components are removed (e . g. , by washing) under conditions such that any complexes formed will remain immobilized on the εolid surface. The detection of complexes anchored on the solid surface can be accomplished in a number of ways. Where the previously non-immobilized component is pre-labeled, the detection of label immobilized on the surface indicates that complexes were formed. Where the previously non-immobilized component iε not pre-labeled, an indirect label can be uεed to detect complexes anchored on the surface; e. g. , using a labeled antibody specific for the previously non-immobilized component (the antibody, in turn, may be directly labeled or indirectly labeled with a labeled anti-Ig antibody) . Alternatively, a reaction can be conducted in a liquid phase, the reaction products separated from unreacted components, and complexes detected; e . g . , uεing an immobilized antibody εpecific for Hcen-2 gene product or the teεt compound to anchor any complexes formed in solution, and a labeled antibody specific for the other component of the possible complex to detect anchored complexes. 5.8.2. ASSAYS FOR INTRACELLULAR PROTEINS THAT INTERACT WITH Hcen-2 GENE PRODUCTS Any method suitable for detecting protein-protein interactions may be employed for identifying Hcen-2 gene product-protein interactionε. Among the traditional methods that may be employed are co-immunoprecipitation, crosε-linking and co-purification through gradientε or chro atographic columns. Utilizing procedures such as theεe allowε for the identification of proteinε, including intracellular proteins, that interact with Hcen-2 gene products. Once isolated, such a .protein can be identified and can be used in conjunction with standard techniqueε, to identify proteins it interacts with. For example, at least a portion of the amino acid sequence of a protein that interacts with the Hcen-2 gene product can be aεcertained uεing techniques well known to thoεe of skill in the art, such as via the Edman degradation technique (see, e.g., Creighton, 1983, "Proteins: Structureε and Molecular Principleε," W.H. Freeman & Co., N.Y., pp.34-49). The amino acid sequence obtained may be uεed as a guide for the generation of oligonucleotide mixtureε that can be uεed to screen for gene εequenceε encoding εuch proteinε. Screening made be accompliεhed, for example, by εtandard hybridization or PCR techniqueε. Techniques for the generation of oligonucleotide mixtures and the screening are well-known. (See, e.g. , Ausubel, supra , and 1990, "PCR Protocols: A Guide to Methods and Applications," Innis, et al . , eds. Academic Preεε, Inc., New York). Additionally, methodε may be employed that result in the simultaneous identification of geneε that encode a protein which interactε with an Hcen-2 gene product. These methods include, for example, probing expreεsion libraries with labeled Hcen-2 gene product, using Hcen-2 gene product in a manner similar to the well known technique of antibody probing of λgtll libraries. One method that detects protein interactions in vivo, the two-hybrid syεtem, iε deεcribed in detail for illustration only and not by way of limitation. One version of this εystem has been described (Chien, et al . , 1991, Proc. Natl. Acad. Sci. USA, 88, 9578-9582) and iε commercially available from Clontech (Palo Alto, CA) . Briefly, utilizing εuch a εystem, plasmidε are constructed that encode two hybrid proteins: one conεists of the DNA-binding domain of a transcription activator protein fused to the Hcen-2 gene product and the other consiεtε of the transcription activator protein's activation domain fused to an unknown protein that iε encoded by a cDNA that haε been recombined into this plaεmid aε part of a cDNA library. The DNA-binding domain fuεion plasmid and the cDNA library are transformed into a strain of the yeast Saccharomyces cereviεiae that containε a reporter gene (e.g., HBS or lacZ) whoεe regulatory region contains the transcription activator's binding site. Either hybrid protein alone cannot activate transcription of the reporter gene: the DNA-binding domain hybrid cannot becauεe it doeε not provide activation function and the activation domain hybrid cannot becauεe it cannot localize to the activator 'ε binding sites. Interaction of the two hybrid proteinε reconεtituteε the functional activator protein and reεultε in expresεion of the , reporter gene, which is detected by an assay for the reporter gene product. The two-hybrid εystem or related methodologies may be used to screen activation domain libraries for proteinε that interact with the "bait" gene product. By way of example, and not by way of limitation, Hcen-2 gene productε may be uεed aε the bait gene product. Total genomic or cDNA sequenceε are fuεed to the DNA encoding an activation domain. This library and a plasmid encoding a hybrid of a bait Hcen-2 gene product fused to the DNA-binding domain are co- transformed into a yeast reporter εtrain, and the reεulting transformants are εcreened for thoεe that expreεs the reporter gene. For example, a bait Hcen-2 gene sequence, such as the open reading frame of the Hcen-2 gene, can be cloned into a vector εuch that it iε tranεlationally fuεed to the DNA encoding the DNA-binding domain of the GAL4 protein. Theεe colonies are purified and the library plasmids responsible for reporter gene expression are isolated. DNA sequencing iε then uεed to identify the proteinε encoded by the library plasmids. A cDNA library of the cell line from which proteins that interact with bait Hcen-2 gene product are to be detected can be made using methods routinely practiced in the art. According to the particular system described herein, for example, the cDNA fragments can be inserted into a vector εuch that they are translationally fuεed to the tranεcriptional activation domain of GAL4. Such a library can be co-tranεformed along with the bait Hcen-2 gene-GAL4 fuεion plaεmid into a yeast strain that contains a lacZ gene driven by a promoter that contains GAL4 activation sequence. A cDNA encoded protein, fuεed to a GAL4 transcriptional activation domain that interactε with bait Hcen-2 gene 5 product will reconεtitute an active GAL4 protein and thereby drive expreεsion of the HIS3 gene. Colonies that expresε HIS3 can be detected by their growth on petri diεheε containing εemi-solid agar based media lacking hiεtidine. The cDNA can then be purified from these εtrains, and used to produce and isolate the bait Hcen-2 gene product-interacting protein uεing techniqueε routinely practiced in the art. 5.8.3. ASSAYS FOR COMPOUNDS THAT INTERFERE WITH Hcen-2 GENE PRODUCT MACROMOLECULE INTERACTION The Hcen-2 gene products may, in vivo, interact with one or more macromolecules, including intracellular macromolecule , εuch aε proteinε. Such macromoleculeε may include, but are not limited to, nucleic acid molecules and those proteinε identified via methods such as those described, above, in Sections 5.8.1 - 5.8.2. For purposes of this diεcuεεion, the macromoleculeε are referred to herein aε "binding partners". Compounds that diεrupt Hcen-2 gene product binding to a binding partner may be uεeful in regulating the activity of the Hcen-2 gene product, especially mutant Hcen-2 gene products. Such compounds may include, but are not limited to molecules εuch aε peptideε, and the like, as described, for example, in Section 5.8.2 above. The baεic principle of an assay system used to identify compounds that interfere with the interaction between the Hcen-2 gene product and a binding partner or partners involveε preparing a reaction mixture containing the Hcen-2 gene product and the binding partner under conditionε and for a time εufficient to allow the two to interact and bind, thus forming a complex. In order to test a compound for inhibitory activity, the reaction mixture is prepared in the presence and absence of the test compound. The teεt compound may be initially included in the reaction mixture, or may be added at a time subsequent to the addition of Hcen-2 gene product and its binding partner. Control reaction mixtures are incubated without the test compound or with a compound which is known not to block complex formation. The formation of any complexes between the Hcen-2 gene product and the binding partner is then detected. The formation of a complex in the control reaction, but not in the reaction mixture containing the test compound, indicateε that the compound interferes with the interaction of the Hcen-2 gene product and the binding partner. Additionally, complex formation within reaction mixtures containing the test compound and normal Hcen-2 gene product may also be compared to complex formation within reaction mixtures containing the test compound and a mutant Hcen-2 gene product. This comparison may be important in those caseε wherein it iε deεirable to identify compounds that disrupt interactionε of mutant but not normal Hcen-2 gene product. The assay for compounds that interfere with the interaction of the Hcen-2 gene products and binding partners can be conducted in a heterogeneous or homogeneouε format. Heterogeneous asεays involve anchoring either the Hcen-2 gene product or the binding partner onto a solid support and detecting complexes formed on the solid support at the end of the reaction. In homogeneous assays, the entire reaction is carried out in a liquid phaεe. In either approach, the order of addition of reactantε can be varied to obtain different information about the compounds being tested. For example, test compounds that interfere with the interaction between the Hcen-2 gene products and the binding partnerε, e .g. , by competition, can be identified by conducting the reaction in the preεence of the test substance; i .e . , by adding the test subεtance to the reaction mixture prior to or simultaneously with the Hcen-2 gene product and interactive intracellular binding partner. Alternatively, test compounds that disrupt preformed complexeε, e . g. , compoundε with higher binding constants that displace one of the componentε from the complex, can be teεted by adding the teεt compound to the reaction mixture after complexes have been formed. The various formatε are deεcribed briefly below. In a heterogeneouε assay syεtem, either the Hcen-2 gene product or the interactive binding partner, iε anchored onto a solid surface, while the non-anchored specieε iε labeled, either directly or indirectly. In practice, microtiter plates are conveniently utilized. The anchored species may be immobilized by non-covalent or covalent attachments. Non- covalent attachment may be accomplished simply by coating the solid surface with a solution of the Hcen-2 gene product or binding partner and drying. Alternatively, an immobilized antibody specific for the species to be anchored may be used to anchor the species to the solid surface. The surfaces may be prepared in advance and stored. In order to conduct the aεεay, the partner of the immobilized εpecies is exposed to the coated surface with or without the test compound. After the reaction iε complete, unreacted components are removed (e .g. , by washing) and any complexeε formed will remain immobilized on the εolid εurface. The detection of complexeε anchored on the εolid surface can be accomplished in a number of ways. Where the non-immobilized εpecies is pre-labeled, the detection of label immobilized on the εurface indicateε that complexes were formed. Where the non-immobilized specieε iε not pre- labeled, an indirect label can be uεed to detect complexeε anchored on the εurface; e.g., uεing a labeled antibody εpecific for the initially non-immobilized εpecieε (the antibody, in turn, may be directly labeled or indirectly labeled with a labeled anti-Ig antibody) . Depending upon the order of addition of reaction componentε, teεt compoundε that inhibit complex formation or that diεrupt preformed complexes can be detected. Alternatively, the reaction can be conducted in a liquid phase in the presence or absence of the teεt compound, the reaction products separated from unreacted components, and complexes detected; e.g., using an immobilized antibody εpecific for one of the binding componentε to anchor any complexes formed in solution, and a labeled antibody specific for the other partner to detect anchored complexes. Again, depending upon the order of addition of reactantε to the liquid phaεe, teεt compoundε that inhibit complex formation or that diεrupt preformed complexes can be identified. In an alternate embodiment of the invention, a homogeneous asεay can be used. In this approach, a preformed complex of the Hcen-2 gene product and the interactive binding partner is prepared in which either the Hcen-2 gene product or its binding partners is labeled, but the signal generated by the label is quenched due to complex formation (see, e .g. , U.S. Patent No. 4,109,496 by Rubenstein which utilizes this approach for immunoassays) . The addition of a test substance that competes with and displaces one of the εpecieε from the preformed complex will reεult in the generation of a εignal above background. In thiε way, test substances that disrupt Hcen-2 gene product/binding partner interaction can be identified. In another embodiment of the invention, theεe εame techniques can be employed using peptide fragmentε that correεpond to the binding domainε of the Hcen-2 product and/or the binding partner (in caεeε where the binding partner iε a protein) , in place of one or both of the full length proteins. Any number of methods routinely practiced in the art can be used to identify and isolate the binding sites. These methods include, but are not limited to, utageneεiε of the gene encoding one of the proteinε and εcreening for diεruption of binding in a co- immunoprecipitation aεεay. Co penεating mutationε in the gene encoding the εecond εpecieε in the complex can then be εelected. Sequence analyεis of the genes encoding the respective proteins will reveal the mutationε that correεpond to the region of the protein involved in interactive binding. Alternatively, one protein can be anchored to a εolid εurface uεing methods described in this Section above, and allowed to interact with and bind to its labeled binding partner, which haε been treated with a proteolytic enzyme, εuch aε trypsin. After washing, a short, labeled peptide compriεing the binding domain may remain aεsociated with the solid material, which can be isolated and identified by amino acid sequencing. Alεo, once the gene coding for the segmentε iε engineered to express peptide fragments of the protein, it can then be teεted for binding activity and purified or synthesized. For example, and not by way of limitation, an Hcen-2 gene product can be anchored to a solid material as described, above, in this Section by making a GST-Hcen-2 fusion protein and allowing it to bind to glutathione agarose beads. The binding partner can be labeled with a radioactive isotope, such as 35 S, and cleaved with a proteolytic enzyme such as trypsin. Cleavage productε can then be added to the anchored GST-Hcen-2 fuεion protein and allowed to bind. After waεhing away unbound peptideε, labeled bound material, representing the binding partner binding domain, can be eluted, purified, and analyzed for amino acid εequence by well-known methodε. Peptides so identified can be produced synthetically or produced using recombinant DNA technology. 5.8.4. ASSAYS FOR IDENTIFICATION OF COMPOUNDS THAT AMELIORATE AN Hcen-2 MEDIATED DISORDER Compounds, including but not limited to binding compounds identified via assay techniques such as those described, above, in Sections 5.8.1 - 5.8.4, can be tested for the ability to ameliorate symptomε of an Hcen-2 mediated diεorder. It should be noted that the assays described herein can identify compounds that affect Hcen-2 activity by either affecting Hcen-2 gene expression or by affecting the level of Hcen-2 gene product activity. For example, compounds may be identified that are involved in another εtep in the pathway in which the Hcen-2 gene and/or Hcen-2 gene product iε involved and, by affecting this same pathway may modulate the effect of Hcen-2 on the development of an Hcen-2 mediated disorder. Such compounds can be used as part of a therapeutic method for the treatment of the disorder. Deεcribed below are cell-based and animal model-based aεεayε for the identification of compounds exhibiting such an ability to ameliorate εympto s of an Hcen-2 mediated disorder. First, cell-based syεtems can be used to identify compoundε that may act to ameliorate εymptomε of an Hcen-2 mediated diεorder. Such cell εyεtemε can include, for example, recombinant or non-recombinant cell, such aε cell lines, that expresε the Hcen-2 gene. In utilizing εuch cell εyεtems, cells that expresε Hcen- 2 may be exposed to a compound suεpected of exhibiting an ability to ameliorate symptomε of an Hcen-2 mediated disorder, at a εufficient concentration and for a εufficient time to elicit εuch an amelioration of εuch εymptoms in the exposed cells. After exposure, the cells can be assayed to measure alterations in the expreεεion of the Hcen-2 gene, e .g. , by aεεaying cell lysates for Hcen-2 mRNA transcriptε (e .g. , by Northern analyεiε) or for Hcen-2 gene productε expressed by the cell; compounds that modulate expression of the Hcen-2 gene are good candidates as therapeuticε. In addition, animal-baεed systemε or models for an Hcen- 2 mediated diεorder, for example, tranεgenic mice containing a human or altered form of Hcen-2 gene, may be uεed to identify compounds capable of ameliorating εymptoms of the diεorder. Such animal modelε may be uεed aε test substrates for the identification of drugs, pharmaceuticals, therapies and interventionε. For example, animal modelε may be expoεed to a compound εuεpected of exhibiting an ability to ameliorate εymptoms, at a sufficient concentration and for a sufficient time to elicit such an amelioration of εymptomε of an Hcen-2 mediated disorder. The response of the animals to the exposure may be monitored by aεεessing the reverεal of the εymptomε of the diεorder. With regard to intervention, any treatmentε that reverεe any aεpect of εymptomε of an Hcen-2 mediated diεorder, εhould be considered as candidates for human therapeutic intervention in such a diεorder. Doεages of test agents may be determined by deriving doεe-response curves, as discuεεed in Section 5.10.1, below. 5.9. COMPOUNDS AND METHODS FOR THE TREATMENT OF Hcen-2 MEDIATED DISORDERS Described below are methods and compositions whereby an Hcen-2 mediated disorder, may be treated. For example, such _ methodε can compriεe adminiεtering compoundε which modulate the expression of a mammalian Hcen-2 gene and/or the synthesis or activity of a mammalian Hcen-2 gene product so symptoms of the disorder are ameliorated. Alternatively, in those instances whereby the mammalian 0 Hcen-2 mediated disorders reεult from Hcen-2 gene mutationε, εuσh methodε can comprise supplying the mammal with a nucleic acid molecule encoding an unimpaired Hcen-2 gene product such that an unimpaired Hcen-2 gene product is expressed and symptoms of the disorder are ameliorated. 5 In another embodiment of methods for the treatment of mammalian Hcen-2 mediated disorders resulting from Hcen-2 gene mutations, such methods can comprise supplying the mammal with a cell comprising a nucleic acid molecule that encodes an unimpaired Hcen-2 gene product such that the cell expresses the unimpaired Hcen-2 gene product and symptoms of the disorder are ameliorated. In caseε in which a loεε of normal Hcen-2 gene product function reεultε in the development of a Hcen-2 mediated disorder an increaεe in Hcen-2 gene product activity would _ facilitate progreεε towards an asymptomatic state in individuals exhibiting a deficient level of Hcen-2 gene expression and/or Hcen-2 gene product activity. Methods for enhancing the expression or synthesiε of Hcen-2 can include, for example, methods such as those described below, in 3 „ Λ 0 Section 5.9.2. Alternatively, symptoms of Hcen-2 mediated disorders, may be ameliorated by administering a compound that decreaseε the level of Hcen-2 gene expression and/or Hcen-2 gene product activity. Methods for inhibiting or reducing the 3 _ level of Hcen-2 gene product syntheεiε or expreεεion can include, for example, methods such as those described in Section 5.9.1. 5.9.1. INHIBITORY ANTISENSE, RIBOZYME AND TRIPLE HELIX APPROACHES In another embodiment, symptomε of Hcen-2 mediated disorders may be ameliorated by decreasing the level of Hcen- _ 2 gene expression and/or Hcen-2 gene product activity by using Hcen-2 gene sequences in conjunction with well-known antisense, gene "knock-out," ribozyme and/or triple helix methods to decrease the level of Hcen-2 gene expression. Among the compounds that may exhibit the ability to modulate 0 the activity, expression or synthesis of the Hcen-2 gene, including the ability to ameliorate the symptoms of a Hcen-2 mediated disorder, are antisenεe, ribozyme, and triple helix moleculeε. Such molecules may be designed to reduce or inhibit either unimpaired, or if appropriate, mutant target S gene activity. Techniques for the production and uεe of εuch moleculeε are well known to thoεe of εkill in the art. Antisense RNA and DNA molecules act to directly block the translation of mRNA by hybridizing to targeted mRNA and preventing protein translation. Antisenεe approaches involve _ the design of oligonucleotides that are complementary to a target gene mRNA. The antisense oligonucleotides will bind to the complementary target gene mRNA transcripts and prevent translation. Absolute complementarity, although preferred, is not required. A sequence "complementary" to a portion of an RNA, aε referred to herein, means a sequence having sufficient complementarity to be able to hybridize with the RNA, forming a stable duplex; in the case of double-stranded antisense nucleic acids, a single strand of the duplex DNA may thus be tested, or triplex formation may be assayed. The ability to hybridize will depend on both the degree of complementarity and the length of the antisenεe nucleic acid. Generally, the longer the hybridizing nucleic acid, the more base mismatcheε with an RNA it may contain and εtill form a εtable duplex (or _ triplex, aε the case may be) . One skilled in the art can ascertain a tolerable degree of mismatch by use of standard procedures to determine the melting point of the hybridized complex. In one embodiment, oligonucleotides complementary to non-coding regionε of the Hcen-2 gene could be used in an antisenεe approach to inhibit tranεlation of endogenous Hcen- 2 mRNA. Antisense nucleic acids εhould be at least six nucleotideε in length, and are preferably oligonucleotideε ranging from 6 to about 50 nucleotideε in length. In εpecific aspects the oligonucleotide is at least 10 nucleotides, at least 17 nucleotides, at least 25 nucleotides or at least 50 nucleotides. Regardless of the choice of target sequence, it iε preferred that in vitro studies are first performed to quantitate the ability of the antisense oligonucleotide to inhibit gene expresεion. It iε preferred that theεe εtudies utilize controls that distinguish between antisenεe gene inhibition and nonspecific biological effects of oligonucleotides. It is also preferred that these εtudies compare levels of the target RNA or protein with that of an internal control RNA or protein. Additionally, it is envisioned that results obtained using the antisense oligonucleotide are compared with those obtained using a control oligonucleotide. It is preferred that the control oligonucleotide is of approximately the same length as the test oligonucleotide and that the nucleotide sequence of the oligonucleotide differs from the antiεenεe εequence no more than iε necessary to prevent specific hybridization to the target sequence. The oligonucleotides can be DNA or RNA or chimeric mixtures or derivativeε or modified versions thereof, single- εtranded or double-εtranded. The oligonucleotide can be modified at the baεe moiety, εugar moiety, or phoεphate backbone, for example, to improve εtability of the molecule, hybridization, etc. The oligonucleotide may include other appended groupε εuch aε peptideε (e .g. , for targeting hoεt cell receptorε in vivo) , or agentε facilitating tranεport acroεs the cell membrane (see, e.g., Letsinger, et al . , 1989, Proc. Natl. Acad. Sci. U.S.A. 86, 6553-6556; Lemaitre, et al., 1987, Proc. Natl. Acad. Sci. U.S.A. 84, 648-652; PCT Publication No. WO88/09810, published December 15, 1988) or the blood-brain barrier (see, e .g. , PCT Publication No. WO89/10134, published April 25, 1988), hybridization- triggered cleavage agents (εee, e .g. , Krol et al . , 1988, BioTechniqueε 6, 958-976) or intercalating agentε (see, e .g. , Zon, 1988, Pharm. Reε. 5, 539-549). To thiε end, the oligonucleotide may be conjugated to another molecule, e .g. , a peptide, hybridization triggered croεε-linking agent, tranεport agent, hybridization-triggered cleavage agent, etc. The antisense oligonucleotide may comprise at least one modified base moiety which iε εelected from the group including but not limited to 5-fluorouracil, 5-bromouracil, 5-chlorouracil, 5-iodouracil, hypoxanthine, xanthine, 4-acetylcytoεine, 5-(carboxyhydroxylmethyl) uracil, 5-carboxymethylaminomethyl-2-thiouridine, 5-carboxymethylaminomethyluracil, dihydrouracil, beta-D- galactoεylqueoεine, inoεine, N6-iεopentenyladenine, 1-methylguanine, 1-methylinoεine, 2,2-dimethylguanine, 2-methyladenine, 2-methylguanine, 3-methylcytosine, 5-methylcytosine, N6-adenine, 7-methylguanine, 5-methylaminomethyluracil, 5-methoxyaminomethyl-2-thiouracil, beta-D-mannoεylqueoεine, 5'-methoxycarboxymethyluracil, 5-methoxyuracil, 2-methylthio-N6-iεopentenyladenine, uracil-5-oxyacetic acid (v) , wybutoxoεine, pεeudouracil, queosine, 2-thiocytoεine, 5-methyl-2-thiouracil, 2-thiouracil, 4-thiouracil, 5-methyluracil, uracil- 5-oxyacetic acid methylester, uracil-5-oxyacetic acid (v) , 5-methyl-2-thiouracil, 3-(3-amino-3-N-2-carboxypropyl) uracil, (acp3)w, and 2, 6-diaminopurine. The antisense oligonucleotide may also comprise at least one modified sugar moiety selected from the group including but not limited to arabinose, 2-fluoroarabinose, xyluloεe, and hexoεe. In yet another embodiment, the antisenεe oligonucleotide compriεeε at leaεt one modified phosphate backbone εelected from the group consisting of a phosphorothioate, a phoεphorodithioate, a phoεphoramidothioate, a phoεphoramidate, a phoεphordiamidate, a methylphosphonate, an alkyl phosphotriester, and a formacetal or analog thereof. 5 In yet another embodiment, the antisense oligonucleotide is an α-anomeric oligonucleotide. An α-anomeric oligonucleotide forms specific double-stranded hybrids with complementary RNA in which, contrary to the usual S-units, the strands run parallel to each other (Gautier, et al., 10 1987, Nucl. Acids Res. 15, 6625-6641). The oligonucleotide is a 2'-0-methylribonucleotide (Inoue, et al . , 1987, Nucl. Acids Res. 15, 6131-6148), or a chimeric RNA-DNA analogue (Inoue, et al . , 1987, FEBS Lett. 215, 327-330). Oligonucleotides of the invention may be syntheεized by 15 εtandard methodε known in the art, e.g., by use of an automated DNA synthesizer (such as are commercially available from Biosearch, Applied Bioεystems, etc.). As examples, phosphorothioate oligonucleotideε may be εyntheεized by the method of Stein, et al . (1988, Nucl. Acidε Res. 16, 3209), 20 methylphosphonate oligonucleotides can be prepared by use of controlled pore glasε polymer εupportε (Sarin, et al . , 1988, Proc. Natl. Acad. Sci. U.S.A. 85, 7448-7451), etc. While antiεenεe nucleotideε complementary to the target gene coding region εequence could be uεed, those 25 complementary to the transcribed, untranslated region are most preferred. Antisenεe moleculeε εhould be delivered to cells that express the target gene in vivo . A number of methods have been developed for delivering antisense DNA or RNA to cells; 30 e .g. , antisense molecules can be injected directly into the tissue site, or modified antisenεe moleculeε, deεigned to target the deεired cellε (e.g., antisense linked to peptides or antibodies that specifically bind receptors or antigens expressed on the target cell surface) can be administered 35 εyεtemically. However, it iε often difficult to achieve intracellular concentrationε of the antisense εufficient to εuppreεε translation of endogenous mRNAs. Therefore a preferred approach utilizes a recombinant DNA construct in which the antisense oligonucleotide is placed under the control of a strong pol III or pol II promoter. The use of such a construct to transfect target cells in the patient will result in the transcription of sufficient amounts of single stranded RNAs that will form complementary base pairs with the endogenous target gene transcripts and thereby prevent translation of the target gene mRNA. For example, a vector can be introduced e .g. , such that it is taken up by a cell and directs the transcription of an antisense RNA. Such a vector can remain episomal or become chromoεomally integrated, as long as it can be transcribed to produce the desired antisenεe RNA. Such vectors can be constructed by recombinant DNA technology methods standard in the art. Vectors can be plasmid, viral, or others known in the art, used for replication and expression in mammalian cells. Expression of the sequence encoding the antisenεe RNA can be by any promoter known in the art to act in mammalian, preferably human cellε. Such promoterε can be inducible or constitutive. Such promoterε include but are not limited to: the SV40 early promoter region (Bernoist and Chambon, 1981, Nature 290, 304-310), the promoter contained in the 3' long terminal repeat of Rous εarcoma virus (Yamamoto, et al . , 1980, Cell 22, 787-797), the herpes thymidine kinaεe promoter (Wagner, et al., 1981, Proc. Natl. Acad. Sci. U.S.A. 78, 1441-1445) , the regulatory sequences of the metallothionein gene (Brinster, et al . , 1982, Nature 296, 39-42), etc. Any type of plaεmid, coεmid, YAC or viral vector can be used to prepare the recombinant DNA construct which can be introduced directly into the tisεue εite. Alternatively, viral vectorε can be uεed that εelectively infect the deεired tiεεue, in which caεe adminiεtration may be accompliεhed by another route (e .g. , εystemically) . Ribozyme molecules designed to catalytically cleave target gene mRNA transcripts can also be used to prevent translation of target gene mRNA and, therefore, expression of target gene product. (See, e .g. , PCT International Publication WO90/11364, published October 4, 1990; Sarver, et al . , 1990, Science 247, 1222-1225). Ribozymes are enzymatic RNA molecules capable of 5 catalyzing the specific cleavage of RNA. (For a review, see Rossi, 1994, Current Biology 4, 469-471). The mechanism of ribozyme action involves εequence εpecific hybridization of the ribozyme molecule to complementary target RNA, followed by an endonucleolytic cleavage event. The composition of 0 ribozyme molecules must include one or more sequenceε complementary to the target gene mRNA, and muεt include the well known catalytic εequence reεponεible for mRNA cleavage. For this sequence, see, e.g., U.S. Patent No. 5,093,246, which is incorporated herein by reference in itε entirety. 15 While ribozymes that cleave mRNA at site specific recognition sequenceε can be uεed to deεtroy target gene mRNAε, the uεe of hammerhead ribozymes is preferred. Hammerhead ribozymeε cleave mRNAε at locations dictated by flanking regions that form complementary baεe pairε with the 20 target mRNA. The sole requirement is that the target mRNA have the following sequence of two baseε: 5'-UG-3'. The construction and production of hammerhead ribozymes is well known in the art and is described more fully in Myers, 1995, Molecular Biology and Biotechnology: A Comprehensive Desk 25.Reference, VCH Publiεherε, New York, (εee especially Figure 4, page 833) and in Haseloff and Gerlach, 1988, Nature, 334, 585-591, which is incorporated herein by reference in itε entirety. Preferably the ribozyme iε engineered so that the 30 cleavage recognition site is located near the 5' end of the target gene mRNA, i.e., to increase efficiency and minimize the intracellular accumulation of non-functional mRNA tranεcripts. The ribozymes of the present invention also include RNA 35 endoribonucleases (hereinafter "Cech-type ribozymes") such as the one that occurs naturally in Tetrahymena thermophila (known as the IVS, or L-19 IVS RNA) and that has been extensively described by Thomas Cech and collaborators (Zaug, et al . , 1984, Science, 224, 574-578; Zaug and Cech, 1986, Science, 231, 470-475; Zaug, et al . , 1986, Nature, 324, 429- 433; published International patent application No. WO 88/04300 by University Patents Inc.; Been and Cech, 1986, Cell, 47, 207-216). The Cech-type ribozymes have an eight base pair active εite which hybridizeε to a target RNA εequence whereafter cleavage of the target RNA takes place. The invention encompasseε those Cech-type ribozymes which target eight base-pair active site sequenceε that are preεent in the target gene. Aε in the antiεenεe approach, the ribozymeε can be compoεed of modified oligonucleotideε (e .g. , for improved εtability, targeting, etc.) and εhould be delivered to cells that expresε the target gene in vivo . A preferred method of delivery involveε uεing a DNA conεtruct "encoding" the ribozyme under the control of a εtrong conεtitutive pol III or pol II promoter, εo that tranεfected cellε will produce εufficient quantitieε of the ribozyme to deεtroy endogenouε target gene meεεageε and inhibit tranεlation. Because ribozyraeε unlike antisense molecules, are catalytic, a lower intracellular concentration iε required for efficiency. Endogenouε target gene expreεεion can alεo be reduced by inactivating or "knocking out" the target gene or its promoter using targeted homologous recombination (e .g. , see Smithies, et al . , 1985, Nature 317, 230-234; Thomas and Capecchi, 1987, Cell 51, 503-512; Thompεon, et al . , 1989, Cell 5, 313-321; each of which is incorporated by reference herein in its entirety) . For example, a mutant, non- functional target gene (or a completely unrelated DNA εequence) flanked by DNA homologous to the endogenous target gene (either the coding regions or regulatory regions of the target gene) can be used, with or without a εelectable marker and/or a negative εelectable marker, to tranεfect cellε that expreεε the target gene in vivo . Inεertion of the DNA construct, via targeted homologous recombination, resultε in inactivation of the target gene. Such approacheε are particularly suited in the agricultural field where modifications to ES (embryonic stem) cells can be used to generate animal offspring with an inactive target gene (e .g. , see Thomas and Capecchi, 1987 and Thompson, 1989, supra) . However this approach can be adapted for use in humans provided the recombinant DNA constructs are directly administered or targeted to the required site in vivo using appropriate viral vectors. Alternatively, endogenous target gene expresεion can be reduced by targeting deoxyribonucleotide εequenceε complementary to the regulatory region of the target gene (i.e., the target gene promoter and/or enhancerε) to form triple helical εtructureε that prevent tranεcription of the target gene in target cellε in the body. (See generally, Helene, 1991, Anticancer Drug Deε., 6(6), 569-584; Helene, et al . , 1992, Ann. N.Y. Acad. Sci., 660, 27-36; and Maher, 1992, Bioaεεayε 14(12), 807-815). Nucleic acid moleculeε to be uεed in triplex helix formation for the inhibition of transcription should be single stranded and composed of deoxynucleotideε. The baεe compoεition of theεe oligonucleotideε must be designed to promote triple helix formation via Hoogsteen base pairing rules, which generally require sizeable stretcheε of either purines or pyrimidineε to be present on one εtrand of a duplex. Nucleotide sequenceε may be pyrimidine-baεed, which will reεult in TAT and CGC + tripletε across the three associated strandε of the reεulting triple helix. The pyrimidine-rich molecules provide base complementarity to a purine-rich region of a single strand of the duplex in a parallel orientation to that εtrand. In addition, nucleic acid moleculeε may be choεen that are purine-rich, for example, contain a εtretch of G reεidueε. Theεe moleculeε will form a triple helix with a DNA duplex that is rich in GC pairs, in which the majority of the purine residues are located on a single strand of the targeted duplex, resulting in GGC triplets across the three strandε in the triplex. Alternatively, the potential sequenceε that can be targeted for triple helix formation may be increaεed by creating a εo called "εwitchback" nucleic acid molecule. Switchback molecules are syntheεized in an alternating 5' -3', 3'-5' manner, εuch that they base pair with first one strand of a duplex and then the other, eliminating the necessity for a sizeable stretch of either purines or pyrimidines to be present on one εtrand of a duplex. In inεtanceε wherein the antisense, ribozyme, and/or triple helix molecules described herein are utilized to inhibit mutant gene expresεion, it iε poεεible that the technique may so efficiently reduce or inhibit the tranεcription (triple helix) and/or tranεlation (antisense, ribozyme) of mRNA produced by normal target gene alleles that the possibility may arise wherein the concentration of normal target gene product present may be lower than is necessary for a normal phenotype. In such cases, to ensure that subεtantially normal levelε of target gene activity are maintained, therefore, nucleic acid molecules that encode and express target gene polypeptides exhibiting normal target gene activity may, be introduced into cells via gene therapy methods such as those described, below, in Section 5.9.2 that do not contain εequenceε susceptible to whatever antisense, ribozyme, or triple helix treatments are being utilized. Alternatively, in inεtances whereby the target gene encodes an extracellular protein, it may be preferable to co- administer normal target gene protein in order to maintain the requisite level of target gene activity. Anti-senεe RNA and DNA, ribozyme, and triple helix molecules of the invention may be prepared by any method known in the art for the synthesiε of DNA and RNA moleculeε, as discussed above. These include techniques for chemically syntheεizing oligodeoxyribonucleotideε and oligoribonucleotideε well known in the art such as for example εolid phaεe phoεphoramidite chemical εyntheεiε. Alternatively, RNA moleculeε may be generated by in vitro and in vivo transcription of DNA sequenceε encoding the antiεense RNA molecule. Such DNA εequenceε may be incorporated into a wide variety of vectorε that incorporate εuitable RNA polymerase promoters εuch aε the T7 or SP6 polymerase promoters. Alternatively, antisenεe cDNA conεtructε that synthesize antiεenεe RNA constitutively or inducibly, depending on the promoter used, can be introduced stably into cell lines. 5.9.2. GENE REPLACEMENT THERAPY Hcen-2 gene nucleic acid sequences, described above in Section 5.1, can be utilized for the treatment of an Hcen-2 mediated disorder. Such treatment can be in the form of gene replacement therapy. Specifically, one or more copies of a normal Hcen-2 gene or a portion of the Hcen-2 gene that directs the production of an Hcen-2 gene product exhibiting normal Hcen-2 gene function, may be inserted into the appropriate cells within a patient, using vectors that include, but are not limited to adenovirus, adeno-associated virus, and retrovirus vectorε, in addition to other particleε that introduce DNA into cellε, εuch as liposomes. Because the Hcen-2 gene iε expreεsed in the brain, such gene replacement therapy techniques should be capable delivering Hcen-2 gene sequences to these cell typeε within patientε. Thuε, in one embodiment, techniqueε that are well known to thoεe of εkill in the art (εee, e . g. , PCT Publication No. WO89/10134, publiεhed April 25, 1988) can be used to enable Hcen-2 gene sequenceε to croεε the blood-brain barrier readily and to deliver the εequences to cells in the brain. With respect to delivery that is capable of crossing the blood-brain barrier, viral vectors such as, for example, those described above, are preferable. In another embodiment, techniques for delivery involve direct administration of such Hcen-2 gene sequences to the site of the cells in which the Hcen-2 gene sequences are to be expresεed. Additional methods that may be utilized to increase the overall level of Hcen-2 gene expression and/or Hcen-2 gene product activity include the introduction of appropriate Hcen-2-expressing cells, preferably autologouε cellε, into a patient at poεitionε and in numbers that are sufficient to ameliorate the symptoms of an Hcen-2 mediated diεorder. Such cells may be either recombinant or non-recombinant. Among the cellε that can be adroiniεtered to increaεe the overall level of Hcen-2 gene expression in a patient are normal cells, preferably brain cellε, that expreεε the Hcen-2 gene. Alternatively, cellε, preferably autologouε cellε, can be engineered to expreεε Hcen-2 gene sequences, and may then be introduced into a patient in positionε appropriate for the amelioration of the εymptomε of an Hcen-2 mediated diεorder. Alternately, cellε that expreεs an unimpaired Hcen-2 gene and that are from a MHC matched individual can be utilized, and may include, for example, brain cells. The expreεsion of the Hcen-2 gene sequenceε is controlled by the appropriate gene regulatory sequences to allow such expresεion in the necessary cell types. Such gene regulatory sequenceε are well known to the εkilled artiεan. Such cell-baεed gene therapy techniqueε are well known to thoεe εkilled in the art, εee, e.g., Anderεon, U.S. Patent No. 5,399,349. When the cellε to be adminiεtered are non-autologouε cells, they can be administered using well known techniques that prevent a host immune response against the introduced cellε from developing. For example, the cells may be introduced in an encapsulated form which, while allowing for an exchange of components with the immediate extracellular environment, does not allow the introduced cells to be recognized by the host immune syεtem. Additionally, compounds, such as those identified via techniqueε such as those described, above, in Section 5.8, that are capable of modulating Hcen-2 gene product activity can be administered uεing standard techniques that are well known to those of εkill in the art. In inεtances in which the compounds to be administered are to involve an interaction with brain cells, the administration techniques εhould include well known oneε that allow for a crossing of the blood-brain barrier. 5.10. PHARMACEUTICAL PREPARATIONS AND METHODS OF ADMINISTRATION The compounds that are determined to affect Hcen-2 gene expression or gene product activity can be administered to a patient at therapeutically effective doses to treat or ameliorate an Hcen-2 mediated diεorder. A therapeutically 0 effective dose refers to that amount of the compound sufficient to result in amelioration of symptoms of such a disorder. 5.10.1. EFFECTIVE DOSE 5 Toxicity and therapeutic efficacy of such compoundε can be determined by standard pharmaceutical procedures in cell cultures or experimental animalε, e.g., for determining the LD JO (the doεe lethal to 50% of the population) and the ED^ (the dose therapeutically effective in 50% of the o population) . The dose ratio between toxic and therapeutic effects is the therapeutic index and it can be expressed as the ratio LD 5 o/ED 50 . Compounds that exhibit large therapeutic indices are preferred. While compounds that exhibit toxic side effects may be used, care should be taken to design a 5 delivery syεtem that targets such compounds to the εite of affected tiεεue in order to minimize potential damage to uninfected cells and, thereby, reduce side effects. The data obtained from the cell culture assays and animal studieε can be uεed in formulating a range of doεage 0 for uεe in humanε. The doεage of εuch compoundε lies preferably within a range of circulating concentrations that include the ED 50 with little or no toxicity. The dosage may vary within this range depending upon the dosage form employed and the route of administration utilized. For any 5 compound used in the method of the invention, the therapeutically effective doεe can be estimated initially from cell culture assays. A dose may be formulated in animal modelε to achieve a circulating plasma concentration range that includes the IC^ (i .e . , the concentration of the test compound that achieves a half-maximal inhibition of symptoms) as determined in cell culture. Such information can be used to more accurately determine useful doses in humans. Levels in plasma may be measured, for example, by high performance liquid chromatography. 5.10.2. FORMULATIONS AND USE Pharmaceutical compositions for use in accordance with the present invention may be formulated in conventional manner using one or more physiologically acceptable carrierε or excipients. Thus, the compounds and their physiologically acceptable saltε and εolvates may be formulated for administration by inhalation or insufflation (either through the mouth or the nose) or oral, buccal, parenteral or rectal administration. For oral administration, the pharmaceutical compo itions may take the form of, for example, tablets or capsules prepared by conventional means with pharmaceutically acceptable excipients such as binding agents (e . g. , pregelatinised maize starch, polyvinylpyrrolidone or hydroxypropyl methylcelluloεe) ; fillerε (e .g. , laσtoεe, microcryεtalline cellulose or calcium hydrogen phosphate) ; lubricants (e .g. , magnesium stearate, talc or εilica) ; diεintegrantε (e .g. , potato εtarch or εodium starch glycolate) ; or wetting agents (e .g. , sodium lauryl sulphate). The tablets may be coated by methods well known in the art. Liquid preparations for oral administration may take the form of, for example, solutionε, syrups or suεpensions, or they may be preεented as a dry product for constitution with water or other εuitable vehicle before uεe. Such liquid preparations may be prepared by conventional means with pharmaceutically acceptable additives such as suεpending agentε (e .g. , sorbitol εyrup, celluloεe derivativeε or hydrogenated edible fatε) ; emulεifying agentε (e .g. , lecithin or acacia); non-aqueouε vehicleε (e.g., almond oil, oily eεterε, ethyl alcohol or fractionated vegetable oilε) ; and preservatives (e.g., methyl or propyl-p-hydroxybenzoates or εorbic acid) . The preparationε may alεo contain buffer εalts, flavoring, coloring and sweetening agents as appropriate. Preparations for oral administration may be suitably formulated to give controlled release of the active compound. For buccal adminiεtration the compositions may take the form of tablets or lozenges formulated in conventional manner. For adminiεtration by inhalation, the compounds for use according to the present invention are conveniently delivered in the form of an aerosol εpray presentation from pressurized packs or a nebuliser, with the use of a suitable propellant, e.g., dichlorodifluoromethane, trichlorofluororaethane, dichlorotetrafluoroethane, carbon dioxide or other εuitable gaε. In the caεe of a preεsurized aerosol the dosage unit may be determined by providing a valve to deliver a metered amount. Capsules and cartridges of e.g., gelatin for use in an inhaler or insufflator may be formulated containing a powder mix of the compound and a suitable powder baεe εuch aε lactose or starch. The compounds may be formulated for parenteral administration by injection, e.g., by bolus injection or continuous infusion. Formulations for injection may be presented in unit dosage form, e.g., in ampouleε or in multi- dose containers, with an added preservative. The compositionε may take εuch formε as suεpenεions, εolutionε or emulεionε in oily or aqueous vehicleε, and may contain formulatory agentε εuch as suspending, stabilizing and/or dispersing agents. Alternatively, the active ingredient may be in powder form for constitution with a εuitable vehicle, e .g. , εterile pyrogen-free water, before use. The compounds may alεo be formulated in rectal compoεitionε εuch aε εuppoεitorieε or retention enemaε, e .g. , containing conventional suppository bases such as cocoa butter or other glycerides. In addition to the formulations deεcribed previously, the compoundε may alεo be formulated as a depot preparation. Such long acting formulations may be administered by implantation (for example subcutaneously or intramuscularly) or by intramuscular injection. Thus, for example, the compounds may be formulated with suitable polymeric or hydrophobic materials (for example as an emulsion in an acceptable oil) or ion exchange resinε, or as sparingly soluble derivatives, for example, as a sparingly soluble salt. The co poεitions may, if desired, be presented in a pack or dispenser device that may contain one or more unit dosage forms containing the active ingredient. The pack may for example comprise metal or plastic foil, such aε a bliεter pack. The pack or dispenser device may be accompanied by instructionε for administration. EXAMPLE: LOCALIZATION OF THE Hcen-2 GENE 0 TO CHROMOSOME 18 In the Example preεented in thiε Section, studies are described that, first, define an interval approximately 310 kb on the εhort arm of human chromoεome 18 within which a region aεεociated with a neuropsychiatric disorder is located _ and, second, to the identification of the Hcen-2 gene, aε mapping within thiε region. 6.1. MATERIALS AND METHODS 6.1.1. LINKAGE DISEQUILIBRIUM 0 Linkage disequilibrium (LD) studieε were performed uεing DNA from a population sample of neuropεychiatric diεorder (BP-I) patientε. The population εample and LD techniqueε were aε deεcribed in Freimer et al., 1996, Nature Geneticε 12:436-441. The preεent LD εtudy took advantage of the additional phyεical markers identified via the physical mapping techniques described below. 6.1.2. YEAST ARTIFICIAL CHROMOSOME . YAC. MAPPING For phyεical mapping, yeaεt artificial chromoεomes (YACs) containing human sequences were mapped to the region being analyzed based on publicly available maps (Cohen et al . , 1993, C.R. Acad. Sci. 316, 1484-1488). The YACε were then ordered and contig reconstructed by performing standard short tag sequence (STS) -content mapping with microsatellite markers and non-polymorphic STSs available from databaεeε that εurround the genetically defined candidate region. 6.1.3. BACTERIAL ARTIFICIAL CHROMOSOME .BAC. MAPPING STSε from the short arm of human chromosome 18 were used to screen a human BAC library (Research Geneticε, Huntεville, AL) . The endε of the BACε were cloned or directly εequenced. The end εequenceε were uεed to amplify the next overlapping BACε. From each BAC, additional microsatelliteε were identified. Specifically, random sheared libraries were prepared from overlapping BACs within the defined genetic interval. BAC DNA was sheared with a nebulizer (CIS-US Inc. , Bedford, MA) . Fragments in the size range of 600 to 1,000 bp were utilized for the εublibrary production. Microεatellite εequenceε from the εublibraries were identified by corresponding microsatellite probeε. Sequences around such repeats were obtained to enable development of PCR primerε for genomic DNA. 6.1.4. RADIATION HYBRID (RHΪ MAPPING Standard RH mapping techniqueε were applied to a Stanford G3 RH mapping panel (Reεearch Geneticε, Huntsville, AL) to order all microsatellite markers and non-polymorphic STSs in the region being analyzed. 6.1.5. SAMPLE SEQUENCING Random sheared libraries were made from all the BACε within the defined genetic region. Approximately 9,000 subclones within the approximately 310 kb region were sequenced with vector primers in order to achieve an 8-fold sequence coverage of the region. All εequences were processed through an automated sequence analysis pipeline that assessed quality, removed vector sequences and masked repetitive εequences. The resulting sequences were then compared to public DNA and protein databases using BLAST algorithms (Altschul, et al . , 1990, J. Molec. Biol., 215, 403-410) . 6.2. RESULTS Genetic regions involved in bipolar affective diεorder (BAD) human geneε had previously been reported to map to portions of the long (18q) and short (18p) arms of human chromosome 18, including a broad I8q genetic region of about 6-7 cM between markers D18S469 and D18S554 (U.S. Provisional Applications Serial Nos. 60/014,498 and 60/023,438, filed on March 28, 1996 and August 23, 1996, reεpectively, the entire contentε of each of which are incorporated herein by reference; Freimer, et al . , 1996, Neuropsychiat. Genet. 67, 254-263; Freimer, et al . , 1996, Nature Genetics 12, 436-441), the entire contents of each of which are incorporated herein by reference. Linkage Diseguilibrium. Prior to attempting to identify gene εequenceε, εtudies were performed to further narrow the neuropsychiatric disorder region. Specifically, a linkage disequilibrium (LD) analyεiε waε performed uεing population samples and techniques aε deεcribed in Section 6.1, above, which took advantage of the additional phyεical markers identified via the physical mapping techniques described below. High resolution physical mapping uεing YAC. BAC and RH technioυeε. In order to provide the preciεe order of genetic markerε necessary for linkage and LD mapping, and to guide new microsatellite marker development for finer mapping, a high resolution physical map of the 18q23 candidate region waε developed uεing YAC, BAC and RH techniques. For εuch phyεical mapping, first, YACs were mapped to the chromoεome 18 region being analyzed. Uεing the mapped YAC contig aε a framework, the region from publicly available markers D18S1161 and D18S554, which spans most of the D18S469-D18S554 region described above, waε alεo mapped and contiged with BACs. Sublibraries from the contiged BACs were constructed, from which microsatellite marker sequences were identified and sequenced. To ensure development of an accurate phyεical map, the radiation hybrid (RH) mapping technique waε independently applied to the region being analyzed. RH was used to order all microsatellite markers and non-polymorphic STSs in the region. Thus, the high reεolution phyεical map ultimately conεtructed waε obtained using data from RH mapping and STS- content mapping. BAC clones within the newly identified 310 kb neuropsychiatric diεorder region were analyzed to identify εpecific genes within the region. A combination of sample sequencing, cDNA εelection and transcription mapping analyses were combined to arrange sequenceε into tentative tranεcription units, that iε, tentatively delineating the coding εequenceε of geneε within thiε genomic region of intereεt. One of the transcription units identified was termed Hcen-2. The present invention is not to be limited in scope by the specific embodiments described herein, which are intended as single illustrations of individual aspects of the invention, and functionally equivalent methods and componentε are within the εcope of the invention. Indeed, variouε modificationε of the invention, in addition to those shown and described herein will become apparen to thoεe εkilled in the art from the foregoing deεcription and accompanying drawings. Such modifications are intended to fall within the scope of the appended claims. All publications and patent applicationε mentioned in thiε εpecification are herein incorporated by reference to the εame extent aε if each individual publication or patent application was εpecifically and individually indicated to be incorporated by reference.

Claims: WHAT IS CLAIMED IS: 1. A method for determining whether a human subject has or is at risk for developing an Hcen-2 mediated neuropsychiatric disorder comprising the step of detecting the presence or absence of a genetic mutation in the Hcen-2 gene (SEQ ID No. 1) of said subject, wherein said genetic mutation is selected from the group consisting of a nucleotide subεtitution, a nucleotide inεertion and a nucleotide deletion and reεults in the production of an Hcen- 2 protein having an amino acid sequence other than the wild- type Hcen-2 amino acid sequence and the presence of said genetic mutation identifies a εubject that haε or is at risk for developing an Hcen-2 mediated neuropsychiatric diεorder. 2. The method of Claim 1, further compriεing the steps of: a) obtaining a sample comprising nucleic acid molecules from said subject; b) amplifying nucleic acid molecules in said sample that encode an Hcen-2 protein using amplification primers that selectively anneal to and amplify nucleic acid molecules that encode said Hcen-2 protein; and c) determining whether said genetic mutation is present. 3. The method of Claim 2, wherein said determination step c) comprises sequencing said nucleic acid molecule that encodes said Hcen-2 protein. 4. The method of Claim 1, wherein the nucleotide sequence of said nucleic acid molecule that encodes said Hcen-2 protein iε determined. 5. The method of Claim 1, further compriεing the εtepε of: a) obtaining a εample compriεing nucleic acid moleculeε from said subject; b) detecting the nucleic acid molecules in said sample that encode said Hcen-2 protein using a nucleic acid probe that selectively hybridizes to nucleic acid molecules that encode said Hcen-2 protein; and c) determining whether said genetic mutation is present. 6. The method of Claim 1, further comprising the steps of: a) obtaining a sample comprising nucleic acid molecules from said εubject; b) detecting the nucleic acid moleculeε in εaid εample that encode εaid Hcen-2 protein uεing a reεtriction endonucleaεe digeεtion of εaid nucleic acid moleculeε and a nucleic acid probe that εelectively hybridizeε to nucleic acid molecules that encode said Hcen-2 protein, or a fragment thereof; and c) determining whether said genetic mutation is present. 7. The method of Claim 1, wherein said genetic mutation is a base change. 8. The method of Claim 1, wherein said genetic mutation is detected by determining whether an altered Hcen-2 protein is produced in εaid εubject. 9. The method of Claim 8, further compriεing the steps of: a) obtaining a sample compriεing protein moleculeε from εaid εubject; b) detecting the Hcen-2 proteinε in εaid sample using an antibody which binds to said Hcen-2 protein; c) determining whether said Hcen-2 protein is encoded by a nucleic acid molecule containing said genetic mutation. 10. A method for identifying a compound that can be used to treat a Hcen-2 mediated neuropsychiatric disorder, comprising the steps of: a) contacting a test compound with an Hcen-2 protein; b) determining whether said test compound binds to said Hcen-2 prptein; and c) selecting a test compound that binds to said Hcen-2 protein as being a compound that can be used to treat an Hcen-2 medicated neuropsychiatric diεorder. 11. The method of Claim 11, wherein an Hcen-2 having wild-type activity iε uεed. 12. The method of Claim 11, wherein an Hcen-2 having an altered activity is used. 13. A method for identifying compounds that can be used to treat an Hcen-2 mediated neuropsychiatric disorder comprising the steps of: a) incubating a cell that expresses an Hcen-2 gene in the presence and absence of a test compound; b) determining the activity of the Hcen-2 gene product in the presence and absence of said test compound; and c) selecting a test compound that alters the activity of εaid Hcen-2 gene product aε being a compound that can be uεed to treat an Hcen-2 mediated neuropεychiatric diεorder. 14. The method of Claim 13, wherein an Hcen-2 having wild-type activity iε used. 15. The method of Claim 13, wherein an Hcen-2 having an altered activity is used. 16. The method of Claim 1, wherein said Hcen-2 mediated neuropsychiatric disorder is bi-polar affected disorder.

Inventors: CHEN HONG, FREIMER NELSON B, CHEN, HONG, FREIMER, NELSON, B.
Applicants: MILLENNIUM PHARM INC, UNIV CALIFORNIA, MILLENNIUM PHARMACEUTICALS, INC., THE REGENTS OF THE UNIVERSITY OF CALIFORNIA
Application year: 1999
Main classification: A61K
IPC codes: A61K45, A61P25, C07K5, C07K14, C07K16, C12N15, C12Q1, G01N33