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J R Kidd

Publications and source records attributed to J R Kidd.

At least 19 recordsLinked to original sources
PubMed1992

Presymptomatic testing using DNA markers for individuals at risk for familial multiple endocrine neoplasia 2A.

The carrier status of 39 at-risk individuals in 6 multiple endocrine neoplasia 2A families was determined using a DNA based test. We were able to calculate a virtual diagnosis (probability greater than 95%) for 77% of the individuals and a probable diagnosis (probability greater than 90%) for 90% of the individuals. This study points out some of the problems of specific pedigree structures that can affect the risk calculation. This study further shows that no single test based on either biochemistry, pathology, or genetics can consistently and unambiguously produce a presymptomatic diagnosis. We also describe two specific examples where DNA testing has helped to resolve clinical uncertainties in at-risk individuals.

Adolescent↗
PubMed1991

Drift, admixture, and selection in human evolution: a study with DNA polymorphisms.

Accuracy of evolutionary analysis of populations within a species requires the testing of a large number of genetic polymorphisms belonging to many loci. We report here a reconstruction of human differentiation based on 100 DNA polymorphisms tested in five populations from four continents. The results agree with earlier conclusions based on other classes of genetic markers but reveal that Europeans do not fit a simple model of independently evolving populations with equal evolutionary rates. Evolutionary models involving early admixture are compatible with the data. Taking one such model into account, we examined through simulation whether random genetic drift alone might explain the variation among gene frequencies across populations and genes. A measure of variation among populations was calculated for each polymorphism, and its distribution for the 100 polymorphisms was compared with that expected for a drift-only hypothesis. At least two-thirds of the polymorphisms appear to be selectively neutral, but there are significant deviations at the two ends of the observed distribution of the measure of variation: a slight excess of polymorphisms with low variation and a greater excess with high variation. This indicates that a few DNA polymorphisms are affected by natural selection, rarely heterotic, and more often disruptive, while most are selectively neutral.

Animals↗
PubMed1991

Studies of three Amerindian populations using nuclear DNA polymorphisms.

Three Amerindian populations, two from Rondônia, Brazil (Karitiana and Rondônia Suruí), and one from Campeche, Mexico (Mayan), were typed for up to 30 nuclear restriction fragment length polymorphisms (RFLPs). Heterozygosities, both observed and expected, were compared with those of Europeans. Average heterozygosity is reduced among these Amerindians (relative to that of Europeans) by 7.0% (Mayan) to 27.1% (Karitiana). This amount of heterozygosity in the nuclear DNA is nevertheless high enough that it is unlikely that there was a severe or prolonged bottleneck.

Alleles↗
PubMed1991

Study of an additional 58 DNA markers in five human populations from four continents.

One hundred DNA polymorphisms from 73 loci (42 genes and 31 anonymous DNA segments) were investigated in five populations (Biaka and Mbuti Pygmies, Melanesians, Chinese and Caucasoids). Data for 47 polymorphisms, including 42 of those discussed here, were described previously [Bowcock et al 1987]. Here we report statistical quantities of genetic importance for each gene and population. The average FST for the 100 markers is 0.137 and the average heterozygosity is 0.325. When known genes and anonymous segments are compared there is no significant difference in the average FST values or in the average heterozygosities.

Africa↗
PubMed1991

Progress in the search for genetic linkage with Tourette syndrome: an exclusion map covering more than 50% of the autosomal genome.

Gilles de la Tourette syndrome is a neuropsychiatric disorder with an autosomal dominant mode of inheritance and reduced penetrance at a single genetic locus. Several research groups have genetic linkage studies underway to detect the chromosomal location of the gene that predisposes for this disorder. Strong and clear evidence of linkage has not yet been produced for Tourette syndrome. This paper presents an overview of the methods and progress of the groups centered at Yale University and Erasmus University in excluding linkage from a large portion of the genome. Our labs have screened 228 genetic marker loci for linkage with a gene for this disorder in a series of affected families in the United States, Canada, The Netherlands, and Norway. More than 50% (and perhaps as much as 66%) of the autosomal genome has now been excluded on the assumption that genetic heterogeneity is not an important factor in the Tourette syndrome pedigrees pooled for this summary.

Chromosome Mapping↗
PubMed1990

A refined linkage map for DNA markers around the pericentromeric region of chromosome 10.

A refined genetic linkage map for the pericentromeric region of human chromosome 10 has been constructed from data on 12 distinct polymorphic DNA loci as well as the locus for multiple endocrine neoplasia type 2A (MEN 2A), a dominantly inherited cancer syndrome. The map extends from D10S24 (at 10p13-p12.2) to D10S3 (at 10q21-q23) and is about 70 cM long. Overall, higher female than male recombination frequencies were observed for this region, with the most remarkable female excess in the immediate vicinity of the centromere, as previously reported. Most of the DNA markers in this map are highly informative for linkage and the majority of the interlocus intervals are no more than 6 cM apart. Thus this map should provide a fine framework for future efforts in more detailed mapping studies around the centromeric area. A set of ordered cross-overs identified in this work is a valuable resource for rapidly and accurately localizing new DNA clones isolated from the pericentromeric region.

Chromosome Mapping↗
PubMed1990

Genetic and physical mapping and population studies of a fibronectin receptor beta-subunit-like sequence on human chromosome 19.

A cDNA clone of the beta subunit of human fibronectin receptor (FNRB) detects two different polymorphic loci: (a) a codominant system previously mapped to the pericentromeric region of chromosome 10, the site of the functional FNRB gene; and (b) a dominant system not linked to the first one or to any chromosome 10 marker tested. This second polymorphism is characterized by the presence or absence of a band (or a set of bands). We have used linkage analysis and biotin-labeled in situ hybridization to map this dominant polymorphism to the short arm of chromosome 19; we hypothesize that it may be due to the insertion of part of the cDNA from the chromosome 10 gene into chromosome 19. This "insertion" is polymorphic in all populations studied.

Chromosome Mapping↗
PubMed1990

The locus for the medium-chain acyl-CoA dehydrogenase gene on chromosome 1 is highly polymorphic.

The gene for medium-chain acyl-CoA dehydrogenase (gene symbol ACADM; enzyme symbol MCAD) has been characterized for restriction fragment length polymorphisms (RFLPs) and mapped by linkage analysis to 4.2 cM from D1S2 and 11.7 cM from PGM1. The three RFLP systems described in detail show significant linkage disequilibrium but define four haplotypes with a PIC of 0.58. This makes ACADM informative for linkage mapping and for clinical genetic studies. By linkage studies, the orientation of these three loci relative to the centromere places ACADM most proximal. This is in direct conflict with the regional assignments of ACADM to 1p31 by in situ hybridization and of PGM1 to 1p22.1 by somatic cell studies. We suggest that this somatic cell localization of PGM1 may be incorrect.

Acyl-CoA Dehydrogenases↗
PubMed1990

Segregation and linkage analyses of Tourette's syndrome and related disorders.

Segregation and linkage analyses were performed with data from a large Tourette's syndrome (TS) multigenerational kindred. Results of segregation analyses were remarkably similar to some reported earlier and suggest that the mode of transmission is consistent with autosomal dominant inheritance. The analyses were done using three diagnostic schemes to specify affected family members (TS only; TS or chronic tics [CT]; and TS, CT or obsessive compulsive disorder [OCD]). The estimates of penetrance for the genotypes AA, Aa and aa (A denotes the susceptibility allele) in the analyses including relatives with TS, CT or OCD were 0.99, 0.99 and 0.00, respectively, for males and 0.70, 0.70 and 0.00 for females. Pairwise linkage analyses with 140 marker loci failed to identify a linked marker. However, approximately 30 percent of the genome was excluded as the site of the hypothesized locus for TS.

Child↗
PubMed1990

The genetic defect in multiple endocrine neoplasia type 2A maps next to the centromere of chromosome 10.

Multiple endocrine neoplasia type 2A (MEN2A) is a rare cancer syndrome that is inherited in an apparently autosomal dominant fashion. Previous linkage studies had assigned the MEN2A locus to chromosome 10 in the pericentromeric region. We recently have described several new easily scorable RFLPs for the chromosome 10-specific alpha satellite DNA (the D10Z1) locus that is known, on the basis of previous in situ hybridization experiments, to lie at the centromere. We report here tight linkage between MEN2A and D10Z1, as demonstrated by a maximum lod score of 12.02 at the recombination frequency of zero (1-lod-unit support interval 0-4 cM), indicating that the genetic defect in MEN2A lies in the immediate vicinity of the centromere. By means of a set of ordered polymorphic DNA markers from the pericentromeric region, multipoint as well as pairwise linkage analyses place the MEN2A locus at the middle of a small region (approximately 11 cM) bracketing the centromere with FNRB (at 10p11.2) and RBP3 (at 10q11.2) on either side, providing further support for the centromeric location of the MEN2A locus. Marked sex difference in recombination frequencies exists in this pericentromeric region: significantly (P less than .01) more female than male crossovers were observed across all of the adjacent intervals D10S24-FNRB, FNRB-D10Z1, and D10Z1-RBP3. However, a sex difference was not seen in the 7-cM interval from RBP3 to D10S5, suggesting that large variation in the sex difference in recombination can occur over small chromosomal regions.(ABSTRACT TRUNCATED AT 250 WORDS)

Centromere↗
PubMed1989

Molecular genetic studies in schizophrenia.

Despite many years of research, the genetic factors in schizophrenia are not well understood. Recent developments in DNA technology allow new methods of testing genetic hypotheses in the etiology of this debilitating disorder. We have found evidence against linkage of schizophrenia in a Swedish kindred to markers on chromosome 5; another research group has reported positive evidence for linkage to this same chromosomal region in British and Icelandic families. This article presents a set of data expanded from our previous report, discusses the issue of heterogeneity, and reviews the current status of linkage studies in schizophrenia.

Chromosomes, Human, Pair 5↗
PubMed1988

Evidence against linkage of schizophrenia to markers on chromosome 5 in a northern Swedish pedigree.

Schizophrenia is a severe mental illness with a typically chronic course affecting nearly 1% of the human population. It is generally accepted that genetic factors have an important pathogenic role in a substantial portion of schizophrenia cases; however, despite decades of family studies, there is no agreed-upon mode of inheritance. The discovery of genetic aetiologic factors and resolution of the inheritance pattern(s) will undoubtably emerge from genetic linkage studies. With these objectives in mind, we undertook a linkage project, starting in 1985, in a previously well-documented kindred from north Sweden. Multipoint linkage analyses were used to screen the proximal long arm of chromosome 5 using restriction fragment length polymorphism (RFLP) markers at five loci and the distal long arm using RFLPs at two loci, one of which was the locus for the glucocorticoid receptor. We found strong evidence against linkage between schizophrenia and the seven loci. These results, together with the positive evidence for linkage of schizophrenia with markers in the proximal long arm of chromosome 5 lead us to conclude that the genetic factors underlying schizophrenia are heterogeneous.

Chromosomes, Human, Pair 5↗
PubMed1988

Tyrosine hydroxylase maps to the short arm of chromosome 11 proximal to the insulin and HRAS1 loci.

Tyrosine hydroxylase (TH) is the rate-limiting enzyme for catecholamine biosynthesis and a candidate gene for manic-depressive illness. The TH locus was typed for a BglII RFLP using a cDNA clone Ty7 in four large kindreds. Pairwise analyses and multipoint analyses were carried out to map the TH locus more precisely in the region of the linked markers: D11S12, INS, and HRAS1 on 11p. Results confirm the close linkage between TH with these previously mapped markers and support a most likely ordering which places TH on the side of INS where the centromere lies.

Chromosome Mapping↗
PubMed1988

The human "interferon-beta 2/hepatocyte stimulating factor/interleukin-6" gene: DNA polymorphism studies and localization to chromosome 7p21.

The human interferon-beta 2 gene (IFNB2) product is identical to that for the B-cell stimulation factor-2 (BSF-2), the hybridoma growth factor (HGF) ("interleukin-6"), and the hepatocyte stimulating factor (HSF). Proteins derived from this gene mediate the plasma protein response to tissue injury (acute-phase response) and regulate the growth and differentiation of both B and T cells. By using the enzymes MspI, BstNI, and BglI, three polymorphic systems were detected with probes for the IFNB2 gene. The MspI and BglI polymorphisms are likely to be due to base pair substitutions; the BstNI polymorphism was revealed by nine other enzymes and is likely to be due to DNA insertions within 1 kb of the 3' flanking region of the gene. This region is rich in AT dinucleotides, and slippage at DNA replication may generate the insertions of between 0.07 and 0.23 kb that were observed. The polymorphic MspI site also lies within the vicinity of the fifth exon. The BglI polymorphic site is likely to lie in 5' flanking DNA. The three polymorphisms are separate, and a variety of haplotypes was observed. A low level of linkage disequilibrium exists between the MspI and the BglI alleles. MspI and BstNI polymorphisms were observed in Caucasoids, CAR Pygmies, Zaire Pygmies, Melanesians, and Chinese but at differing frequencies, and not all alleles were present in all populations. The BglI polymorphism was observed in Caucasoids and Africans only. Linkage studies involving the IFNB2 gene and 27 other chromosome 7 markers have localized it to between D7S135 and D7S370 at 7p22-p21.(ABSTRACT TRUNCATED AT 250 WORDS)

Alleles↗
PubMed1988

A linkage group of five DNA markers on human chromosome 10.

Five chromosome 10 DNA markers (D10S1, D10S3, D10S4, D10S5, and RBP3) were typed in five large pedigrees with multiple endocrine neoplasia type 2A (MEN-2A) and in five non-MEN-2A pedigrees. Linkage analyses showed that these loci and the locus for MEN-2A (MEN2A) are in one linkage group spanning at least 70 cM. The order of the marker loci is RBP3-D10S5-D10S3-D10S1-D10S4, with interlocus recombination frequencies of 7, 13-19, 19, and 19%, respectively, all on the same side of MEN2A. Analyses of sex-specific recombination frequencies indicated no significant differences between males and females for any of the map intervals studied. Previous localization of D10S5 and RBP3 to the proximal region of the long arm and the pericentric region, respectively, comparison of results with other studies, and our preliminary results with other chromosome 10 markers suggest that the D10S4 end of the map extends into the long arm. Our linkage map has been constructed using only two- and three-locus analyses. It will be possible to combine our results with those of other groups to construct a more detailed and accurate genetic map of chromosome 10.

Alleles↗
PubMed1988

D10S20, a previously unmapped RFLP (OS-3), is located on 10q near D10S4.

The locus recognized by the probe OS-3 is assigned to chromosome 10 both by Southern blot analysis of a panel of somatic cell hybrid DNAs and by genetic linkage to markers already assigned to chromosome 10. In Caucasians this probe recognizes a three-allele TaqI RFLP as well as two-allele BanII and RsaI RFLPs which are both in strong linkage disequilibrium with each other and with the TaqI RFLP. The D10S20 locus defined by this probe maps 5.5 cM distal to D10S4 on the long arm of chromosome 10. Because this human clone hybridizes with mouse genomic DNA, it will be useful in comparative mapping studies.

Alleles↗