bluuebunny/crossref_metadata_2025_split huggingface dataset:
Fetal death rates in mothers of children with trisomy 21 (Down syndrome)
Authors: Lippman A. , Aymé S. 
Published: September 2007

SummaryWomen under 25 years at the birth of a child with trisomy 21 (Down syndrome) appear to have an increased risk of having another child with a trisomy. If the risk of recurrence is due solely to an increased production of trisomic conceptions, women with an affected child should have a rate of spontaneous abortion higher than average, since the majority of aneuploid conceptuses are expected to be aborted. We examined fetal loss rates among the other pregnancies of 545 women delivered of a child with trisomy 21 and compared the observed loss rates with those which would be expected were the relative risk for these women for an aneuploid recognized pregnancy the same as their relative risk for an aneuploid livebirth as reported by others. Overall loss rates in their prior pregnancies were greatest for women who were 20–24 years old at the time of birth of the proband. Moreover, the observed rate of fetal loss for this group of women (33·8%) was at least as high as that predicted from their relative risk for a trisomic livebirth. By contrast, the observed fetal loss rates for women 25–39 years of age at the proband's birth did not differ from the rates predicted on the assumption that their risk for a trisomic recognized pregnancy was not increased, as the livebirth data suggested. The results of this study suggest that women under 25 years at the birth of a child with trisomy 21 have a significantly higher rate of fetal loss in their prior pregnancies than women delivered of the trisomic child at older ages.
A computer program for constructing a maximum‐likelihood map from linkage data and its application to human chromosome 1
Authors: Wedd N. 
Published: September 2007

SummaryAn algorithm is described which attempts to find the maximum likelihood order of the loci on a chromosome using linkage data. It can also use data on locus order if these are available. A computer program which applies this algorithm has been written, and tested on the data for human chromosome 1. The most likely possible order is GDH, PGD, ENO1, Rh, UMPK, Sc, PGM1, AMY, Fy, CAE, 1qh, CMT1, AT3, PEPC.
Parental origin of autosomal trisomies
Authors: HASSOLD T. , CHIU D. , YAMANE J. A. 
Published: September 2007

SummaryChromosome heteromorphisms of parents and their trisomic spontaneous abortions were compared in an attempt to determine the parental origin of 204 single trisomies, including cases of trisomy 3, 4, 9, 13, 14, 15, 16, 21 and 22, nine mosaic trisomies and nine double trisomies. Non‐disjunction at maternal meiosis I was the most likely source of the additional chromosome for all trisomies studied, including the mosaics, and this was the case at all maternal ages. However, trisomy 21 had a significantly increased proportion of paternally derived cases by comparison with all other trisomies. Consideration of the sex ratio in eases of trisomy 21 of known parental origin suggests that there is an excess of males associated with paternal first meiotic division non‐disjunction. The fact that this mechanism of origin is more prevalent in trisomy 21 may well explain why there is an excess of males associated with this abnormality but not with other autosomal trisomies.
Human myosin heavy chain genes assigned to chromosome 17 using a human cDNA clone as probe
Authors: EDWARDS Y. H. , PARKAR M. , POVEY S. , WEST L. F. , PARRINGTON J. M. , SOLOMON E. 
Published: September 2007

SummaryA cDNA clone complementary to the mRNA encoding human myosin heavy chain has been isolated from a human fetal skeletal muscle cDNA library. A 600 base pair fragment of the inserted human cDNA has been used as probe in the Southern analysis of DNA from panels of rat/human and mouse/human somatic cell hybrids. All the sequences detected by this probe have been mapped to chromosome 17 in the region 17pter → 17p11. There was no evidence for MHC sequences on any other chromosome.
Heritable fragile sites on human chromosomes XII. Population Cytogenetics
Authors: SUTHERLAND G. R. 
Published: September 2007

SummaryChromosome studies to detect the folate sensitive fragile sites have been carried out on 2439 randomly selected neonates. Four autosomal fragile sites were detected in this group. Similar studies were carried out on referred patients, special school students and sheltered workshop employees. The incidence of fragile X in these groups was 6/1936, 13/502 and 0/128 respectively. Autosomal folate sensitive fragile sites were seen in 14/1936, 5/502 and 2/128 individuals respectively.
The structural gene for aldolase B (ALDB) maps to 9q13→32
Authors: HENRY I. , GALLANO P. , BESMOND C. , WEIL D. , MATTEI M. G. , TURLEAU C. , BOUÉ J. , KAHN A. , JUNIEN C. 
Published: September 2007

SummaryWe used a cloned cDNA probe for the B subunit of human aldolase (ALDB) and Southern blotting techniques to analyse DNA from a series of rodent x human somatic cell hybrids for the presence of specific ALDB‐related sequences. Our results provide evidence for the assignment of the gene for ALDB to chromosome 9. Moreover, by direct gene dosage determination in two patients with chromosome 9 unbalanced rearrangements and by in situ hybridization we refined the regional chromosomal assignment to 9q13→q32 and most probably to 9q21.3→9q22.2.
Further studies on chiasma distribution and interference in the human male
Authors: LAURIE D. A. , HULTÉN M. A. 
Published: September 2007

SummarySome unusual patterns of chiasma distribution were noted in a preliminary investigation of meiosis in an infertile male with an apparently normal mitotic karyotype and a normal mean autosomal cell chiasma frequency. A detailed investigation of chiasma distribution on all 22 autosomes revealed that several chromosomes showed a significant change in chiasma distribution and/or mean inter‐chiasma distance in comparison with previously published controls. These findings are discussed in relation to the general patterns of chiasma localization in the human male and the role of interference.
Possible changes in the frequency of the human ABO blood groups in Iceland due to smallpox epidemics selection
Authors: ADALSTEINSSON S. 
Published: September 2007

SummaryThe hypothesis is put forward that the low frequency of A and high frequency of O blood group genes in the Icelandic human population is the result of a selective disadvantage of A during severe smallpox epidemics. The hypothesis is supported by data from India in 1965–6, which show a marked selective effect of a smallpox epidemic against the phenotypes A and AB (Vogel & Chakravartti, 1971). The conclusion is drawn that the present‐day ABO blood group gene frequencies of the Icelandic population should be used with reservation as markers in the study of the origin of the Icelanders.
Use of robust variance components models to analyse triglyceride data in families
Authors: BEATY T. H. , SELF S. G. , LIANG K. Y. , CONNOLLY M. A. , CHASE G. A. , KWITEROVICH P. O. 
Published: September 2007

SummaryA robust approach for analysis of variance components models is presented which does not rely on the assumption of multivariate normality for its validity. This approach uses the multivariate normal distribution as a ‘working model’ but obtains standard errors for the final estimators which do not depend on this underlying distribution. By using the observed variance in the first derivatives of the multivariate normal ‘working model’ to modify the conventional score test, hypotheses regarding specific components can also be tested without relying directly on the assumption of multivariate normality. A special case is presented where both the modified score test and the likelihood ratio test are equally robust, and simulated data are used to illustrate this situation. Measurements of triglyceride levels in 391 individuals in 60 families randomly selected from the membership of a health maintenance organization are used to illustrate this robust approach to variance components.
Assignment of the gene determining human carbonic anhydrase, CAI, to chromosome 8
Authors: EDWARDS Y. H. , BARLOW J. H. , KONIALIS C.P. , POVEY S. , BUTTERWORTH P.H.W. 
Published: September 2007

SummaryA cDNA clone complementary to the mRNA encoding the rabbit erythrocyte specific carbonic anhydrase, CAI, has been used as probe for human CAI sequences in the analysis of DNA from panels of rodent/human somatic cell hybrids. The presence of the human CAI gene in all hybrids correlates with the presence of chromosome 8. Together with published mapping data, this assignment indicates that three CA loci are situated on chromosome 8.
A test statistic for the affected‐sib‐set method
Authors: LANGE K. 
Published: September 2007

SummaryThis paper discusses generalizations of the affected‐sib‐pair method. First, the requirement that sib identity‐by‐descent relations be known unambiguously is relaxed by substituting sib identity‐by‐state relations. This permits affected sibs to be used even when their parents are unavailable for typing. In the limit of an infinite number of marker alleles each of infinitesimal population frequency, the identity‐by‐state relations coincide with the usual identity‐by‐descent relations. Second, a weighted pairs test statistic is proposed that covers affected sib sets of size greater than two. These generalizations make the affected‐sib‐pair method a more powerful technique for detecting departures from independent segregation of disease and marker phenotypes. A sample calculation suggests such a departure for tuberculoid leprosy and the HLAD locus.
Very close linkage between D2S1 and ACP1 on chromosome 2p
Authors: LOTHE R. A. , GEDDE‐DAHL T. , OLAISEN B. , BAKKERS E. , PEARSON P. 
Published: September 2007

SummaryThe genomic DNA‐probe L2.30 was used to assign D2S1 to 2p23–pter by in situ hybridization. The RFLP revealed by BglII was then used for linkage studies in the Oslo‐NHIK families segregating for the acid phosphatase ACPl protein polymorphism. Evidence for very close linkage was found by a lod score of +17.17 at recombination fraction θ= 001. By this close linkage 92 informative meioses could be inferred from the families and with only a single crossover. The upper probability limit to the recombination fraction is 006 according to the HGM 8 criterion. No association between ACP1 alleles and D2S1 BglII alleles was found. The Norwegian gene frequencies for 0251 were A1 (9–0 kb) = 065 and A2 (6.3 kb) = 0.35.
EM investigations of surface spread synaptonemal complexes in a human male carrier of a pericentric inversion inv(13)(p12q14): the role of heterosynapsis for spermatocyte survival
Authors: SAADALLAH N. , HULTÉN M. 
Published: September 2007

SummaryEM investigations of surface spread synaptonemal complexes of pachytene spermatocytes were performed on a human male carrier of a pericentric inv(13), ascertained through his daughter with a duplication‐deficiency of the same chromosome. The inv(13) bivalent could be unambiguously identified by either its asymmetrical kinetochores or its nucleolar association or both. There was scarcity of reversed homosynapsis of the inverted segments with inversion loops, possibly related to the small size of the inversion. The majority of pachytene spermatocytes showed the inverted segment to be either asynapsed or heterosynapsed. Generally initial homosynapsis is highly efficient with high fidelity, while heterosynapsis at the secondary pachytene pairing phase may take place with any available partner remaining unsynapsed and including the differential segments of the XY. It is suggested that survival of spermatocytes to later stages of meiosis may be ensured by heterosynapsis, and the recombinant chromosome in the offspring might be the result of a U‐type exchange.
Maximum likelihood estimation of components of variance and correlations in the analysis of family data
Authors: BENER A. , HUDA S. 
Published: September 2007

SummaryA simple iterative method is developed for computing the maximum likelihood estimates of the components of variance and thereby the intraclass and interclass correlations, under multivariate normal assumptions involving two classes. The method works efficiently for both balanced and unbalanced data and can be readily extended to situations involving three or more classes. It is particularly suitable for application to studies of quantitative variables in genetics and is illustrated by using some dermatoglyphic data.
Family and population studies of SAHH and ADA polymorphisms. A possible pitfall in the ascertainment of SAHH electrophoretic phenotypes
Authors: SCOZZARI R. , SELLITTO D. , TASSONE F. , CERRONI L. , ALIQUÒ M. C. 
Published: September 2007

SummaryTyping of both SAHH and ADA red cell electrophoretic patterns was carried out among the members of about 80 families from Latium (Central Italy) and in a random sample of about 350 individuals from two Italian regions, Latium and Sardinia.1. The SAHH1 enzyme product provided another interesting example of a change in the electrophoretic pattern brought about by the haemolysate ageing. In vitro storage of SAHH 1 red cell lysates leads to the production of a pattern similar to that expected from a heterozygote SAHH 2–1. This change has been shown to be abolished by pretreating the sample with mercaptoethanol.The results indicate that the systematic use of sulphydril reducing agents can provide a more reliable means of analysing the SAHH polymorphism if differently stored samples are to be compared by starch gel electrophoresis.2. Evidence against complete linkage of the SAHH and ADA loci has been obtained from two informative SAHH/ADA matings encountered in this study.3. The SAHH allele frequencies observed in the two samples analysed were: SAHH1= 0.969, SAHH2= 0.024, SAHH3= 0.007 (Latium) and SAHH1= 0.973, SAHH2= 0.011, SAHH3= 0.016 (Sardinia).4. The ADA2 allele frequency estimates were: 0.083 (Latium) and 0.059 (Sardinia). These figures are almost identical to those already reported for the same two regions.
Biological performance in β‐thal heterozygotes and normals: results of a longitudinal comparison in a former malarial environment
Authors: CANELLA R. , BARBUJANI G. , CUCCHI P. , SINISCALCO M. , VULLO C. , BARRAI I. 
Published: September 2007

SummaryFamilies of β‐thal heterozygotes and of normals studied in 1956 by Silvestroni and Bianco in the small town of Berra near Ferrara were studied again in 1981–85. It was possible to compare mortality, fertility, and migration, in the two groups of heterozygotes and normals after the lapse of one generation. At the power of resolution of the sample available and of the methods used, no difference was visible. However, it was possible to establish the upper limits of the differences in average age at death and in average fertility at the 5% level of significance.
Restriction fragment length polymorphisms of the complement component C4 loci on chromosome 6: studies with emphasis on the determination of gene number
Authors: TEISBERG P. , JONASSEN R. , MEVÅG B. , GEDDE‐DAHL T. , OLAISEN B. 
Published: September 2007

SummaryRestriction fragment length polymorphisms of the C4 region of human chromosome 6 have been studied in family material where the haplotypes are defined with regard to other genetic markers in this region. Employing one near full‐length C4 probe and the combination ofBglII andXbaI enzymes, five different C4 genes were characterized. Studies of the segregation of DNA patterns in families made possible the reliable determination of DNA C4 haplotype pattern including gene number. In the total material of 76 haplotypes, 13 different types with regard to number and/or DNA type of C4 gene(s) were encountered. Twelve of the haplotypes had one C4 gene only, 58 had two genes, while 6 had three C4 genes. This fits fairly well with the hypothesis that the one‐ and three‐gene haplotypes have originated through unequal crossing‐over between chromosomes carrying duplicated C4 genes.
Regional localization of CD18, the β‐subunit of the cell surface adhesion molecule LFA‐1, on human chromosome 21 by in situ hybridization
Authors: SOLOMON E. , PALMER R. W. , HING S. , LAW S. K. A. 
Published: September 2007

SummaryThe gene coding for the β‐subunit of the cell surface adhesion glycoprotein LFA‐1 has been localized to the tip of the long arm of chromosome 21 at 21q22.1‐qter.
Mitochondrial DNA polymorphism in four Sardinian villages
Authors: SARTORIS S. , VARETTO O. , MIGONE N. , CAPPELLO N. , PIAZZA A. , FERRARA G. B. , CEPPELLINI R. 
Published: September 2007

SummaryPolymorphism of mitochondrial DNA has been studied in two highland (Desulo, Tonara) and in two lowland (Galtellì, Orosei) Sardinian isolates, formerly subjected to different selective pressure due to malaria, and in 103 individuals from Northern Italy (Bergamo area), where malaria never appeared to be endemic. Two mitochondrial restriction endonuclease patterns (morphs) never described before have been found, one in the Bergamo and Orosei samples, and the other one only in Orosei. Four new mitochondrial types (mitotypes) due to different combinations of morphs have been identified; two of them have been found only in Sardinia, but with such a low frequency that they cannot be defined as typical Sardinian mitotypes. One mitotype (BamHI ‐ morph 3, MspI ‐ morph 4, AvaII ‐ morph 9 and HaeII ‐ morph 1) showed a significantly higher frequency in the highland rather than in the lowland Sardinian villages or in the Bergamo area. Since this mitotype has been found at a relatively high frequency in Central and Southern Italy, while it has been reported to be rare in Caucasians of Central European origin and absent in other ethnic groups (Africans, Chinese, Japanese and Israeli Jews), we suggest it may represent an ancient Mediterranean type. The analysis of these data suggests that drift or other evolutive forces different from malaria might be the major cause of mitochondrial DNA variation in Sardinia.
Effects of environmental changes on the phenotypic expression of human polygenic traits
Authors: ULIZZI L. , CORREANI R. , TERRENATO L. 
Published: September 2007

SummaryThe very large increase in adult stature during the last century is well documented for many countries and this phenomenon has been associated with the rapid improvement of environmental conditions. In the case of Italy, data relative to its regions and drawn from the military records of the last century showed a rapid normalization (i.e. elimination of both negative skewness and hyperkurtosis) of the distribution (1874–1938), followed by acceleration of the average increase (1938–57), which is now approaching a plateau (1957–64). Two different interactions between genotype and environment are hypothesized: the curve normalization is interpreted as being due to the elimination of extremely unfavourable conditions which inhibit growth, while the rapid stature increase is possibly due to the achievement of an environmental threshold, such as to permit a complete expression of the genetic potential. In fact, under the multifactorial model, a perfectly normal distribution is expected, unless there is differential selection before age 18.
Assignment of the gene encoding the beta‐subunit of the human fibronectin receptor (β‐FNR) to chromosome 10p11.2
Authors: Goodfellow P. J. , Nevanlinna H. A. , Gorman P. , Sheer D. , Lam G. , Goodfellow P. N. 
Published: September 2007

SummaryA cDNA corresponding to the β‐subunit of the human fibronectin receptor (β‐FNR) was used as a probe in Southern blot analysis of mouse/human somatic cell hybrid DNAs and in in situ hybridization to metaphase chrmosomes. The β‐FNR cDNA detects sequences prosent on parent of the somatic cell hybrids. In situ hybridization refined the localization of human sequences reacting with the β‐FNR cDNA to 10p11.2. The A‐1A5 monoclonal antibody which recognizes the beta‐subunit of the fibronectin receptor on the cell surface was used to confirm that the sequences present on chromosome 10 correspond to those required for expression of β‐FNR.
Efficient computation of lod scores: genotype elimination, genotype redefinition, and hybrid maximum likelihood algorithms
Authors: Lange K. , Weeks D. E. 
Published: September 2007

SummaryCalculation of multilocus lod scores presents challenging problems in numerical analysis, combinatories, programming, and genetics. It is possible to accelerate these computations by exploiting the simple pedigree structure of a CEPH‐type pedigree consisting of a nuclear family plus all four grandparents. Lathropet al.(1986) have done’ this by introducing likelihood factorization and transformation rules and Lander & Green (1987) by the method of ‘hidden Markov chains’. The present paper explores an alternative approach based on genotype redefinition in the grandparents and systematic phase elimination in all pedigree members. All three approaches accelerate the computation of a single likelihood. Equally relevant to multilocus mapping are search strategies for finding the maximum likelihood estimates of recombination fractions. Hybrid algorithms that start with the EM algorithm and switch midway to quasi‐Newton algorithms show promise. These issues are investigated in the context of a simulated 10 locus example. This same example allows us to illustrate a simple strategy for determining locus order.
Sequence of full length cDNA for human S‐adenosylhomocysteine hydrolase.
Authors: COULTER‐KARIS D.E. , HERSHFIELD M.S. 
Published: September 2007

SUMMARYTwo cDNA clones for human S‐adenosylhomocysteine hydrolase isolated from a placental cDNA library were sequenced. Each contained a sequence of 1299 nucleotides encoding a 432 amino‐acide protein of MW 47660. Clone 16‐1 contained 47 nucleotides 5′ of the coding region, and a 780 nucleotide 3′ flanking region terminating in apoly A tail. In addition, a 101 nucleotide unprocessed intron interrupted the coding sequence at nucleotide 854 (second base of codon 285). Clone 20‐1 contianed 43 nucleotides 5′ and 742 nucleotides 3′ flanking the uninterrupted coding region. Besides the intron, the clones differed in one position of the coding sequence and at two positions of the 3′ non‐coding region. The cDNAs for human and rat S‐adenosylhomocysteine hydrolase were identical at 91.5% of position in the coding sequence and showed 70% homology in the 3′ non‐coding regions. Human and rat S‐adenosylhomocysteine hydrolases are identical at 97% of amino‐acid residues, and the Dictyostelium and human enzymes at 75%.
Isonymy and migration distance
Authors: BARRAI I. , FORMICA G. , BARALE R. , BERETTA M. 
Published: September 2007

SUMMARYThe distribution of surnames of the living immigrants in the population of the town of Ferrara was studied by sex of immigrants and by distance of their place of origin from Ferrara. It was found that isonymy decreases with distance from the place of origin and that there is sexual dimorphism in migration distance: females migrate preferentially at short distances and males at long and very long distances. As indicators of the abundance of surnames in a distribution, the common ecological indices derived from entropy were used, and compared between migration ranges. It was found that redundancy, like isonymy, decreases with migration distance, and that it may be useful in detecting very‐long‐distance migration.