Molecular Genetic Study of Schizophrenia: Parent-Offspring Trios
Condition: Schizophrenia
MeSH terms: Schizophrenia
Study type: Observational

Summary: 
      Schizophrenia is a chronic and devastating major psychiatric disorder. Family, twin, and
      adoption studies indicated that schizophrenia has a significant genetic component. The mode
      of transmission is still not clear and a multilocus model was proposed. The location of
      susceptibility gene of schizophrenia is still under active search using molecular genetic
      methods.

      We propose to collect genomic DNA and lymphoblast cell lines of a total of 150 DSM-IV
      schizophrenic patients and their first degree relatives including parents (parent-offspring
      trios) and non-affected siblings in three years. Adequate statistical power of molecular
      genetic studies is a great concern. For this concern, we will examine the patients and their
      parents clinically by using the Diagnostic Interview for Genetic Studies (DIGS) for
      diagnostic assessment, and by using neuropsychological battery including sustain attention,
      executive function, verbal memory and general intelligence for neuropsychological
      evaluations.

      The project is feasible because (1) The PI and his research team have experience in
      successfully collecting co-affected sib-pair families of schizophrenia and in setting-up
      molecular genetic laboratory in the past decade. We are experienced and competent to execute
      this project. (2) The PI and his research team have established the instruments using to
      clarify the phenotypes including the DIGS, the neuropsychological battery these years.

      Major goals of this project are: (1) to cooperate with this important Taiwan Genotype
      Consortium proposed by the NHRI; (2) to detect major schizophrenia susceptibility genes
      related to the neuropsychological endophenotype; (3) to do further fine mapping on suggestive
      linkage markers to replicate previous linkage studies results using our previously-collected
      co-affected sib-pair family sample; and (4) to deposit the lymphoblast cell lines into NHRI
      Cell Bank serving as a national resource for basic research in Taiwan.
    

Detailed description: 
      1. Specific Aims We propose to collect genomic DNA and lymphoblast cell lines of a total of
           150 families with the probands fulfilling the criteria of DSM-IV schizophrenia in three
           years. The first degree relatives of the probands, including parents (parent-offspring
           trios) and non-affected siblings, a total of about 3 to 6 subjects, will also be
           recruited in study. Adequate statistical power of molecular genetic studies is the great
           concern. For this concern, we will examine the probands and family members clinically by
           using the Diagnostic Interview for Genetic Studies (DIGS) for diagnostic assessment, and
           using neuropsychological battery including sustain attention, executive function, verbal
           memory and general intelligence.

           This specific aims of this project are: (1) to cooperate with this important Taiwan
           Genotyping Consortium proposed by the NHRI; (2) to detect major schizophrenia
           susceptibility genes which are related to the neuropsychological endophenotype; (3) to
           do further fine mapping on suggestive linkage chromosome regions to replicate previous
           linkage studies results using our previously-collected co-affected sib-pair family
           sample; and (4) to deposit the lymphoblast cell lines into NHRI Cell Bank serving as a
           national resource for basic research in Taiwan.

        2. Background

           1. Genetic Basis of Schizophrenia Most family studies confirm that schizophrenia and
           related disorders is a familial disorder and that the risk to first degree relatives of
           schizophrenic patients is approximately ten times the risk to relatives of controls.
           Twin studies have found concordance rates from 46%~53% for MZ twin pairs, and from
           14%~15% for DZ twin pairs (Kendler KS 1983; Gottesman II 1993; Prescott and Gottesman
           II, 1993); thus provide strong evidence for an hereditary component to schizophrenia.
           However, the concordance rates in MZ twins is far from 100% , which also emphasizes the
           importance of environmental factors in the etiology of schizophrenia. The evidence of
           genetic contribution to the etiology of schizophrenia is further supported by adoption
           study. Adoption studies of schizophrenia have shown that when biological offspring of
           schizophrenic mothers were raised by adoptive parents, they showed higher rates of
           schizophrenia as adults, compared to control adoptees.

           Segregation analyses indicate that multifactorial polygenic model, which posit a large,
           unspecified number of loci to combine additively in causing schizophrenia, better fit
           the observed patterns of schizophrenia in family studies than do single major locus
           model. It was suggested that several genes of small effect in epistasis might
           responsible for genetic etiology of schizophrenia.

           The location of susceptibility gene of schizophrenia is still under active search using
           molecular genetic methods. This way of approach included linkage analysis, candidate
           genes association study, and positional candidate gene approach, there is no a priori
           hypothesis that would lead one to focus on any given chromosomal region. Thus, the whole
           genome needs to be systemically screened. A few genome-wide scans of schizophrenia have
           been published for the decade and many chromosome regions showed suggestive evidences
           for linkage, including chromosome 1q21-q22, 1q31-q42, 2p22-q21, 4q24-q32, 6p24-p22,
           6q16-q23, 8p24-p21, 10p14-p13, 13q14-q32, 15q13-q14, 22q11-q13. However, only a few
           chromosome regions were ever reported to have genome-wide significant linkage evidences,
           including chromosome 1q21-q22, 6p24-p22, 8p21 and 13q32.

           Candidate genes studies revealed inconsistent results in the past decade.
           Neurotransmitter related genes, such as dopamine (D1, D2, D3, D4, D5), serotonin,
           r-aminobutyric acid and Glutamate receptor genes had been studied using both association
           and linkage studies and no consistent results obtained. Neuron growth related genes,
           phospholipase genes, and a potassium channel gene (hKCa3/KCNN3) have been reported
           association with schizophrenia. The hypothesis about the pathophysiological mechanism of
           schizophrenia provide the probable candidate genes approach in the molecular genetic
           study. There exists two issues to be resolved for candidate gene approach using
           case-control design. Firstly, a critical issue in assessing the significance of
           association with phenotypic measures is the likelihood of type I errors. Since many
           genes and phenotypes can be evaluated for schizophrenia, the significance level needs to
           be adjusted due to the low prior probability and multiple testing. Secondly, the effects
           of different population admixture between cases and controls may inflate the type I
           errors Positional candidate gene approach using linkage dysequilibrium strategy may
           resolve the above two problems raised by the approach of candidate gene association
           study basing upon the previous linkage results to increase the prior probability and
           using parent-offspring trios as internal control. This approach is more powerful than
           linkage study to locate the susceptibility genes of complex disorder as schizophrenia.
           With the fine mapping linkage evidences, the whole genome sequence and single nucleotide
           polymorphism (SNP) map, and the advancing microarray technique available, this approach
           is more efficient to locate the susceptibility genes of schizophrenia. Recently, a study
           using above strategy has been reported significant linkage dysequilibrium evidence of
           schizophrenia to a microsatellite polymorphism and a SNP of a gene, NOTCH4 gene, at
           chromosome 6p21.

           Considering the potentials of positional candidate gene approach using linkage
           dysequilibrium strategies, we propose to collect parent-offspring trios of schizophrenia
           as the sample of further molecular genetic study of schizophrenia. With our previous and
           ongoing efforts in linkage studies of schizophrenia using co-affected sib-pairs of
           schizophrenia (see preliminary results), this sample can be used for further positional
           candidate gene studies.

           3. Neuropsychological Deficit in Schizophrenia In the domain of neuropsychology,
           schizophrenia have been shown to have unique pattern of impairments in central executive
           function, sustained attention and working memory were rather unique in schizophrenia and
           are suggestive of frontostriatal dysfunction. It was agreed by most researchers that
           neuropsychological impairments of schizophrenia were best demonstrated by comprehensive
           test batteries tapping on various neuropsychological process, rather than single,
           isolated test and at present, the impairments strongly suggested dysfunction of
           frontal-temporal-limbic circuit.

           Among the neuropsychological deficits in schizophrenia, visual sustained attention
           measured by the Continuous Performance Test (CPT) and executive function measured by the
           Wisconsin Card Sorting Test (WCST) were studied more thoroughly. Common features of the
           CPT are that participants must respond to predesignated targets among stimuli that are
           presented at a rapid fixed rate. The discrimination vigilance task of the CPT may
           consist of a single stimulus (CPT-X, single character or number as the target ) or two
           successive stimuli (CPT-AX, a character or number preceded by another character or
           number as the target). The difficulty level of the CPT can be raised further by blurring
           the stimuli (degraded CPT) or using a relative target (CPT-Identical Pairs Version or
           CPT-IP). The different CPT versions might tap on different components of sustained
           attention: the more difficult ones are stable vulnerability indicators, while the
           simpler ones might be mediating vulnerability indicators in schizophrenia. Among studies
           specifically examining the relationships between CPT performance indexes and clinical
           symptom dimensions, one of the most consistent findings is that CPT deficits are
           associated with negative symptoms. Many studies also found that poorer performance on
           the CPT were associated with thought disorder or disorganized symptoms.

           Executive function deficits measured by WCST referred to abnormal function of prefrontal
           cortex. Deficits in WCST performance are enduring and core features of schizophrenia,
           and predict long term disability, independent of other cognitive deficits. Functional
           neuroimaging studies have found that the WCST activates the dorsolateral prefrontal
           cortex and that the dopamimetic drugs improves performance on this task in patients with
           schizophrenia and enhance the signal to noise of the prefrontal physiological response.

           Previous studies confirmed that deficits in sustained attention and executive function
           are specific to schizophrenia and related to schizophrenic pathophysiological process.
           The deficits have also been associated with genetic risk of schizophrenia and may serve
           as an endophenotype in genetic analysis in schizophrenia.

           4. Endophenotype Approach in Molecular Genetic Studies of Schizophrenia To resolve the
           problems of insufficient power of genetic analyses and genetic heterogeneity of
           schizophrenia, an alternative strategy was advocated that the use of a specific
           neurobiological characteristic of the illness as an additional phenotype that might
           reflect more closely the effect of a single genetic alteration.

           The visual sustained attention deficits as measured by CPT was an potential
           endophenotype of the genetic susceptibility to schizophrenia. CPT deficits were present
           not only in schizophrenia patients, but also in their non-psychotic relatives. Using
           data from 148 non-psychotic relatives and 345 community adults found that the recurrence
           risk ratio λwas greater than 15 for the undegraded CPT and greater than 30 for the
           degraded CPT.

           The executive function deficits as measured by WCST may also serve as an endophenotype
           in genetic studies of schizophrenia. WCST deficits presented both in schizophrenic
           patients and their healthy siblings.

           Thus, using CPT deficits and WCST deficits as endophenotypes of schizophrenia would
           provide a valuable measure of genetic risk, would improve the power of genetic analyses
           and may help identify susceptibility genes for schizophrenia.

           This endophenotype strategy has been successful in mapping of a neurophysiological
           deficit of schizophrenia, decrease of P50 inhibition, to loci at chromosome 15q13-14,
           recently. The genome-wide linkage analysis of the P50 inhibition deficit in nine
           multiplex schizophrenia families found a significant lod score (Z = 5.30,  = 0) at a
           loci chromosome 15q14. When the clinical diagnosis of schizophrenia was used as the
           affected phenotype, the maximum lod score at the same marker was not statistically
           significant. The other neurobiological deficit, eye tracking dysfunction of
           schizophrenia has been mapped to chromosome 6p23-21 with the maximum multipoint lod
           score of 4.02. Again, while the clinical diagnosis of schizophrenia was used as the
           affected phenotype, the linkage result was non-significant.

           In summary, with our preliminary studies in linkage analyses using co-affected sib-pairs
           of schizophrenia and neuropsychological deficits in schizophrenia, this project to
           collect schizophrenics of parent-offspring trios with well-defined neuropsychological
           endophenotypes, is considered to be one crucial project for searching the susceptibility
           genes of schizophrenia.

        3. Preliminary Studies

             1. Collection of Schizophrenia Co-affected Sibpairs Family The P.I. has been committed
                himself in collecting the schizophrenia co-affected sib-pairs family since 1990.
                With the awareness of the importance and critical necessity of diagnostic
                assessment, these probands, co-affected sib and available non-affected sib as well
                as the parents were assessed with a semi-structured psychiatrist diagnostic
                interview using diagnostic criteria of DSM-III-R and/or DSM-IV. Besides, under the
                evolutionary theoretical model of psychopathology, developmental data were also
                collected. All these clinical data and family-tree data were established in the
                data bank of the molecular genetic laboratory (DBMGL) in the Department of
                Psychiatry, College of Medicine, National Taiwan University under the auspice of
                the P.I. In total, there are around 120 schizophrenia co-affected sib-pairs
                families available for linkage analysis in the DBMGL. As a rule, the DNA samples
                were obtained from the peripheral white cells of all available subjects of the
                family, especially the co-affected sibs, at least one non-affected sib and the
                parents. In total, around 1000 DNA samples were in the DBMGL. Cell-lines of EBV-958
                transformed lymphoblast cells were established too. All these study subjects were
                well informed for this study and informed consent obtained. All families
                participated in this study were invited to join a "New-Hope Family Club" for
                periodic meeting and discussion. Around 150 schizophrenia cases who received detail
                clinical assessment and regular follow-up and comprehensive neuropsychological
                assessment, including CPT, WCST, WAIS-R, and WMS, were recruited for obtaining DNA
                samples. Around 200 normal control subjects were also recruited for obtaining DNA
                samples.

                The instruments used in genetic studies have been established. The Diagnostic
                Interview Schedule for Genetic Study (DIGS) and schizotypy interview schedule (SIS)
                were translated and modified to be useful in Taiwan subjects. The Perceptual
                aberration scale (PAS) and Schizotypal personality questionnaire (SPQ) were also
                used in community study on schizophrenia-related personality disorders. The
                cross-cultural consideration was employed.

                A 5-year nation-wide collaborative work in Taiwan (Taiwan Schizophrenia Linkage
                Study, TSLS), sponsored by the NIMH, U.S.A., to collect families with co-affected
                sib-pairs with schizophrenia has been going on in the third years. A total of 600
                families will be collected. DNA samples, cell-lines and clinical data of DIGS,
                FIGS, as well as neuropsychological testing data were collected. The DNA sample
                would be open to research teams all over the world.

             2. Molecular Genetic Studies of Schizophrenia Our molecular genetic studies of
                schizophrenia were supported by three consecutive projects: the molecular genetic
                project sponsored by the National Science Council (1989-1992), the molecular
                genetic project of MPGRP (1993-1998) and the molecular genetic project of MPSS
                (1998-2001) sponsored by NHRI. The early phase (1989-1992) of this molecular
                genetic project focused on establishing laboratory facilities and collecting
                co-affected schizophrenic sib-pair families. The 2nd phase of this molecular
                genetic project (1993-1998) continued the collection of families, and the
                collection was extended to collect the co-affected bipolar sib-pairs, schizophrenic
                cases and normal controls. We found the polymorphism of androgen receptor gene of
                (CAG)n had a probable association with schizophrenia. This finding supported the
                finding of DeLisi et al. The molecular genetic methods of linkage analysis and
                candidate gene association were promoted, this laboratory of the P.I. (Dr. Hwu)
                moved to emphasize in this area too. The results of this laboratory were: (1) The
                polymorphism of (48bp) repeats in DRD4 receptor gene was not significantly linked
                with schizophrenia; (2) A single mutation in DRD2 was found not to be associated
                with schizophrenia (3) The samples of the data bank of this project had joined
                three international collaboration studies using positional cloning approach which
                need relatively large sample. The one is organized by Gill et al entitled as
                "Schizophrenia Collaborative Linkage Group", another was led by Dr. Moises in Kiel
                University, Germany and the third one is with Dr. Powell in London. All these
                results revealed the possible markers in chromosomes 6p, 11q, 13q, 19q and 22q.
                This suggests that Taiwanese patients may have possible susceptibility genes in
                these regions, except chromosome 13q, fitting an oligogenetic model. (4) The
                association study on 5-HT2 receptor gene located on chromosome 13q was found to be
                negative; (5) Clinical epidemiological analysis using co-affected sib-pairs
                demonstrated the tendency of 3 independent symptom clusters of reality
                disorganization, disorganization and negative state. (6) Weak linkage evidence to
                loci at chromosome 6p24-22.

                The 3rd phase of the molecular genetic study (1998-2001) continued focusing at
                collecting co-affected schizophrenic sib-pair families and linkage analysis on
                reported suggestive evidences of chromosome regions, including chromosome 1q21-q22,
                1q31-q42, 8p24-p21, 15q13-q14, 22q11-q14. The linkage results were (1) suggestive
                evidence of linkage for schizophrenia with and without the negative symptoms on
                chromosome 6p24 and 22q12 (2) no linkage evidence of GABAA receptor α1 (GABRA1) ,
                β1 (GABRB1) andβ3 (GABAB3) subunit gene with schizophrenia (3) no linkage evidence
                of Glutamate GluR5 and GluR6 receptor gene with schizophrenia (4) no linkage
                evidence of SCA1 gene with schizophrenia (5) suggestive linkage evidence on markers
                of chromosome 8p with schizophrenia (Hwu et al., 2001a) (6) weak linkage evidence
                of markers of chromosome 1q31-42 with schizophrenia (7) suggestive linkage evidence
                of markers on 15q13-14 with schizophrenia (8) modest linkage evidence of
                schizophrenia to loci at chromosome 1q21-22. The candidate gene approach has
                revealed the following results: (1) possible association between Dopamine D4
                receptor (DRD4) gene polymorphism with quick treatment response of schizophrenia
                (Liu et al., 2001d) . (2) no association between cytosolic phospholipase A2
                (c-PLA2) gene polymorphism and schizophrenia.

             3. Studies on Neuropsychological Deficits in Schizophrenia We found impaired sustained
                attention by continuous performance test (CPT) as the trait marker of
                schizophrenia. Family studies have indicated that sustained attention deficits as
                measured by the CPT are vulnerability markers of schizophrenia. The results are:
                (1) a substantial proportion of non-psychotic relatives of schizophrenia probands
                (19-34%) have CPT deficits, which can be predicted from their probands' CPT
                performance; (2) subjects with schizotypal personality features also exhibit CPT
                deficits, which are specifically associated with negative factors of schizotypy;
                (3) CPT deficits are present in schizophrenic patients, are particularly associated
                with negative and disorganized symptoms, and those with more difficult CPT versions
                are not amenable to neuroleptic treatment.

           The specificity of CPT was studied in a group of schizophrenia patients (n=41) in
           contrast to the group of bipolar patients with psychotic symptoms (n=46) and the group
           of bipolar patients without psychotic symptoms (n=22) and a group of patients with
           non-psychotic major depressive disorder (n=22). It was found that CPT deficits are
           stable vulnerable indicators of schizophrenia, mediating vulnerability indicators for
           bipolar disorder, and state-dependent indicator for major depression. These results
           demonstrate that CPT deficits are valid trait marker of schizophrenia.

           All these preliminary data support that the PI and his associates is capable in
           executing this project including collection of parent-offspring trios families, DNA
           extraction and cell culture laboratory techniques, and the neuropsychological
           assessment.

        4. Research Design and Methods

           1. Subjects We prepare to collect parent-offspring trios families from the Medical
           Center of National Taiwan University Hospital and the affiliated psychiatric hospitals,
           the Taoyuan Psychiatric Center. The proband cases to be recruited are the residents of
           the Northern part of Taiwan. Informed consent will be obtained before the recruitment
           for study. The first degree relatives to be recruited are the parents and at least one
           of the unaffected siblings. The diagnosis of the proband cases is of schizophrenia
           defined by DSM-IV criteria.

             1. Clinical Assessment Measures I. The Diagnostic Interview for Genetic Studies (DIGS)
                All subjects will be personally interviewed with the DIGS, which was created by
                Tsuang and Faraone from the NIMH Human Genetics Initiative. The DIGS makes a
                detailed assessment of the course of illness, and makes a careful assessment of
                substance abuse and mood symptoms. This allows for an easier differential diagnosis
                between schizophrenia and substance related psychoses, schizoaffective disorders
                and psychotic mood disorders. This detailed assessment helps protect against false
                positive diagnosis.

                In addition, the DIGS provides a rich description of many domains of
                psychopathology: somatization, major depression, mania/hypomania,
                dysthymia/depressive personality/hyperthymic personality, alcohol abuse disorders,
                pathological gambling, and antisocial personality disorder. It also collects
                self-reported demographic and medical history data. Ratings are also made on the
                Global Assessment Scale and the Scales for the Assessment of Positive and Negative
                Symptoms. Schizotypal and other Axis II Cluster A personality features are assessed
                by using a modified version of the Structured Interview for Schizotypy.

                II. The Family Interview for Genetic Studies (FIGS) As an additional source of
                pedigree information, the FIGS will be conducted with all members of the family.
                This interview systematically questions an informant about the presence of
                psychiatric illness in relatives. We administer the FIGS in three steps. First, the
                structure of the family pedigree is drawn and reviewed with the informant. Next,
                psychiatric screening questions are asked about all relatives in the pedigree. Then
                based on the responses to the screening questions, one or more of five symptom
                checklists (depression, mania, substance abuse, psychosis, paranoid /schizoid/
                schizotypal personality disorder) are completed for each first-degree relative,
                spouse, or other relative well known to the informant.

                The DIGS and FIGS were translated into Chinese. The reliability and validity have
                been established in our preliminary studies.

                III. The Diagnostic Procedure All diagnoses will be made using DSM-IV. These
                diagnoses will be made by two board certified psychiatrists with clinical and
                research experience in the diagnosis of psychotic patients. Final diagnoses of
                probands and relatives will be based on the content of the interview, the case
                vignette, information provided by relatives and a complete review of the medical
                record by each diagnostician. If the two diagnosticians disagree about any of the
                patient's diagnoses, a third diagnostician will be used as a tie-breaker.

                IV. Training of Interviewers The training program will certify the interviewers:
                (1) establish a working knowledge of the diagnostic systems used in the DIGS and
                FIGS; (2) develop expertise in the administration and scoring of the structured
                diagnostic instrument; and (3) fully understand the process of informed consent and
                the need for strict adherence to consent procedures.

                The training program is divided into two stages: (1) formal didactic training and
                (2) supervised experience using the structured diagnostic interview.

                The didactic training begins with trainees reading and familiarizing themselves
                with the diagnostic systems used by the DIGS. This initial exposure is supplemented
                by lectures which review diagnostic criteria for all psychiatric disorders covered
                by the interview. Central issues addressed in these lectures are: (1) the
                importance of establishing diagnoses on the basis of objective behavioral
                description; (2) careful delineation and differentiation of syndromes which involve
                both psychotic and affective phenomena; and (3) clarification of major differences
                in syndrome definition among diagnostic systems.

                The second component of training focuses on the structured diagnostic instruments.
                Trainees first gain familiarity with the structure of the interview. This is
                facilitated by having trainees conduct practice interviews in which they
                alternately play the roles of interviewer and subject. These initial interviews are
                conducted with a senior psychiatrist in attendance to identify problem areas in
                administration and to ensure clinically sensitive use of the interview.

                The training program also includes a module on the modified Structured Interview
                for Schizotypy (SIS). The SIS training includes a review of the literature about
                schizotypal personality disorder, an orientation and review of the instrument, an
                opportunity for trainees to observe and make clinical ratings of a live interview,
                and a review and discussion of clinical ratings to clarify scoring criteria. All
                the training courses have been well established in our preliminary studies.

             2. Neuropsychological Evaluations

                Considering the complexity of the proposed neuropsychological deficits in
                schizophrenia, a test battery tapping multiple aspects of cerebral process is
                chosen to explore patients' overall pattern of neuropsychological deficits. The
                battery consists of tests supposed to measure:

                  1. Sustained attention (the Continuous Performance Test (CPT), both in undegraded
                     and degraded test situations)

                  2. Central executive functions (Wisconsin Card Sorting Test (WCST); Trail-making
                     B);

                  3. Memory function (Weschler Memory Scale-third edition, WMS-III).

                  4. Test for general intellectual achievements (block design; picture completion;
                     information; similarity; arithmetic; digit span; digit symbol substitution).

                The neuropsychological test used in present study and validity of the test battery
                have been well established in our preliminary studies. We prepare to administer the
                neuropsychological test battery to the probands and all the recruited family
                members as possible. The neuropsychological test battery is rather time-consuming,
                estimated to take 3 to 4 hours to complete. Hence, the neuropsychological test
                battery will be administrated in divided sessions, completed in two days. Two
                master degree research assistants majored in psychology will perform all the tests.

           2. Laboratory Work: This project has two lines of laboratory work

             1. Collection of blood samples and extraction of DNA Twenty to thirty ml of venous
                blood will be obtained from all study subjects into purple top and green top
                vacutainer tubes. The blood sample in purple top tubes will be used for DNA
                extraction. We prepare to extract the DNA using a modified salting-out method.

             2. Cell-line set-up All blood samples newly collected will have the lymphocyte
                transformed into lymphoblastic cell for preservation of cell-line which will be
                deposited into the cell bank of NHRI as the proposal requested. The detail
                procedures of cell culture established in our molecular genetic laboratory are
                listed as attached files molecular genetic study.

           3. Data Management We have already set up the computerized DIGS database software in our
           previous study (Taiwan Schizophrenia Linkage Study, TSLS) and neuropsychological
           databank in another previous study (Multidimensional Psychopathological Study for
           Schizophrenia, MPSS). All the clinical and neuropsychological data in this project will
           be incorporated into these databanks.

           The family pedigree data, DNA data, and cell culture data will be incorporated into our
           previously established databank: Bank of Molecular Genetic Laboratory Data (BMGLD). This
           BMGLD will include 4 sets of Data: (1) family tree and genotyping data bank. These data
           are set-up using the cyrillic program ; (2) DNA sample bank; (3) clinical data and
           endophenotype bank and (4) cell-line bank. This well organized BMGLD will be of great
           value for continous research work.

           The data entry procedures will follow the guidelines that we use for our ongoing
           projects. These procedures seek to maximize the accuracy of data. The data will be
           double-entered, and the original and verification files will be compared for
           discrepancies. All datasets will be backed up to disc regularly. The backup and original
           data sets will be maintained in different locked offices.

           The datasets in this project will be available to other investigators following the
           guidelines of the RFA. We will create a dataset which will include all data required by
           the RFA and whatever additional data the NHRI desires to incorporated into the Cell
           Bank. These data will be sent to the data management center designated by the NHRI for
           subsequent distribution to the member of genotyping consortium.

        5. Anticipated Results We anticipate through this project to attain the following goals:
           (1) to cooperate with this important Taiwan Genotyping Consortium proposed by the NHRI,
           (2) to detect major schizophrenia susceptibility genes which are related to the
           neuropsychological endophenotype, (3) to do further fine mapping on suggestive linkage
           chromosome regions to replicate previous linkage studies results using our
           previously-collected co-affected sib-pair family sample, and (4) to deposit the
           lymphoblast cell lines into NHRI Cell Bank serving as a national resource for basic
           research in Taiwan.

        6. Human Subjects This is a genetic study, all subjects recruited will present his signed
           informed consent before being enrolled for study. There is no invasive procedure of
           potential hazard in the process of the clinical interview and the neuropsychological
           evaluations. Blood samples of 30 c.c. will be drawn. This will be done using a needle
           and this may cause some painful sensation which is usually negligible in clinical
           setting. These participating subjects will be reassured as any discomfort feeling
           happens during the study procedures.

           All researchers participated in this study procedure are all well trained. If these is
           any unexpected emotional or physical reaction happens during the study procedure, the
           P.I. of the project should be informed and necessary actions will be taken immediately.
           Since this is a genetic study, in the study procedure, there may have the genetic
           counseling issue raised. The participating researchers will be educated before attending
           this study for this topic of genetic counseling. These subjects or their family who are
           in need of specific genetic counseling will be refer to the special clinic, locating in
           the outpatient department of the National Taiwan University Hospital, of the P.I. of
           this project for special care.

        7. Animal Investigation not involved.

        8. Potential Hazards The clinical interview, the neuropsychological evaluations, and the
           blood sample drawn will be very safe. However, this genetic study might provoke some
           emotional reaction of the family, especially regarding the genetic heritability. In this
           case, the attending researchers, well trained, will give immediate assurance and
           assessment. If anything considered to be necessary, these subjects will be referred to
           the special clinic of the P.I. of this project for special psychiatric care.

      The procedure of blood sample drawing might create mild degree of painful sensation or
      fearful feeling. These cases will be reassured immediately. Generally speaking, this study
      procedure is safe and the potential hazards is minimal and is manageable if anything happen.
    

Observational model: Defined Population
Time perspective: Other
Keywords: Schizophrenia; Niacin; Genotyping; candidate gene; one proband, normal parents and one normal sibling