Search PubMed⌕ Search

Biomedical subjects

T Wienker

Publications and source records attributed to T Wienker.

33 records · Page 2Linked to original sources
PubMed1989

Association and sibpair analysis for the HLA, Gm, Km, and insulin polymorphisms in multiplex IDDM families.

A log-linear model was used to analyze three-way interactions between IDDM and pairs of genetic markers. To do this, a special sample dataset was selected by taking one affected and one unaffected child from each family. Some three-way interactions were found for associations between insulin-dependent diabetes mellitus (IDDM), HLA-DR, and DQ restriction enzyme fragment length polymorphism (RFLP) patterns. No three-way interaction was found for IDDM, HLA-DR, and Gm or Km. An extended sibpair analysis was applied to the HLA-B,DR loci and to the Gm, Km, and insulin gene polymorphisms. The well-known result for IDDM and HLA was reproduced. For Gm, Km, and the insulin gene no cosegregation with IDDM could be found.

Child↗
PubMed1989

Myotonia congenita (Thomsen's disease) excluded from the region of the myotonic dystrophy locus on chromosome 19.

Linkage analysis has been carried out in six German families with autosomal dominantly inherited myotonia congenita (Thomsen's disease) using five chromosome 19 markers known to be linked to the gene for myotonic dystrophy (DM). Two of the markers, APOC1 and APOC2, are tightly linked to DM. Close linkage between these markers and myotonia congenita (MC) has been excluded to a distance of 9 cM (z = -2.158). These data support the clinical suggestion that MC and DM are non-allelic disorders.

Chromosomes, Human, Pair 19↗
PubMed1987

Linkage analysis with RFLPs in families with androgen resistance syndromes: evidence for close linkage between the androgen receptor locus and the DXS1 segment.

Three families with androgen resistance syndromes--two with testicular feminization and one with Reifenstein syndrome--have been studied for linkage analysis. Using three cloned DNA sequences from the centromere region and the proximal long arm of the X chromosome (p8, pDP34, and S9, which define respectively the chromosomal segments DXS1, DXYS1, and DXS17), we found no recombination between the DXS1 locus and the mutant genes in the three families. Assuming that these disorders are the result of allelic mutations at the same locus for the androgen receptor, we can conclude that there is a close linkage between DXS1 and the androgen receptor locus, with a maximum lod score zeta = 3.5 at a recombination fraction theta = 0.0 using the LIPED program (Ott 1974).

Androgen-Insensitivity Syndrome↗
PubMed1986

Dermatoglyphic patterns and pattern intensities of Callicebus (primates: Cebidae): description and comparison of three species.

The palmar and plantar dermatoglyphic pattern types are described for three species of Callicebus (18 Callicebus moloch, 18 Callicebus torquatus and 7 Callicebus personatus). Mean pattern intensities (API) were calculated for each of seven areas of the palm and nine areas of the sole, and a summed mean total pattern intensity (TPI) for each volar surface. Nonparametric statistical testing showed no significant bilateral asymmetry or sexual dimorphism in pattern intensities. Pattern profiles describing the relative relationships of API values across the left palm and sole are presented. The profiles typical of the genus closely resemble those of Aotus and Saimiri. Significant interspecific differences, particularly in the plantar API values, were detected. The results are discussed with reference to the present taxonomic classification of the species of Callicebus and their postulated evolutionary history.

Animals↗
PubMed1977

Haplotype analysis of the linkage group HLA-A:HAL-B:Bf and its bearing on the interpretation of the linkage disequilibrium.

The analysis of 650 HLA-A:HAL-B:Bf three-factor haplotypes revealed significant associations only between alleles of the very closely linked genes HLA-A and HLA-B, and Bf, respectively. Most striking is the highly significnat association of the rare Bf variant F1 with HLA-B18 and of S1 with HLA-B13, HLA-B14, and HLA-Bw21. Only random allele distributions were observed when considering the somewhat more distant genes HLA-A and Bf or the higher order interaction at all three genes. From these findings it seems likely that the linkage disequilibrium within the MHC is not due to selective forces, but rather due to a short evolutionary period.

Chromosomes, Human, 6-12 and X↗
PubMed1977

Adrenoleukodystrophy (Siemerling-creutzfeldt disease): Heterozygote with two clonal fibroblast populations.

On the fifth day after subcultivation,, fibroblasts of two unrelated patients with adrenoleukodystrophy (Siemerling-Creutzfeldt disease (SCD)) developed typical morphologic anomalies which could be seen by light microscopy. From skin biopsy material of an obligatorily heterozygous womam, both normal and morphologically defective colonies could be isolated. These findings suggest that the morphologic alterations are an expression of the defect in Siemerling-Creutzfeldt disease. Futhermore, they suggest that the SCD locus is subject to lyonization.

Adrenal Cortex Diseases↗
PubMedDate not supplied

Mapping genes for polygenic disorders: considerations for study design in the complex trait of inflammatory bowel disease.

While the methodology for the mapping of Mendelian disorders is well established, the practical and theoretical steps required for successful gene identification in a complex trait are still difficult to predict. A number of analytical models and simulations based on repetitive drawings from predefined statistical distributions are available. To supplement these analytical models, we developed an integrated simulation approach by directly simulating entire populations under a disease model based on epidemiological data. Random mating, nonoverlapping populations and the absence of differential fitness were assumed. Samples were drawn from these homogeneous and heterogeneous populations and analyzed with established analysis tools. We investigated the properties of linkage and association studies in inflammatory bowel disease - modeled as a six-locus polygenic disorder - as an example of this approach. In nonparametric linkage studies, lod scores varied widely, with the median required sample size depending on the locus-specific relative sibling risk. A fine mapping resolution <4 cM was found to require nonparametric lod scores >10. Family-based association studies (TDT test) and case-control studies showed a similar sensitivity and can identify risk loci in populations with moderate levels of linkage disequilibrium in sample sizes of 500-800 triplets. Case-control association studies were prone to false-positive results if applied in heterogeneous populations, with the false-positive rate increasing with sample size because population heterogeneity is detected with increasing power.

Alleles↗