Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0012872 (DNA marker)
 929 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A province wide study of carrier detection methods in haemophilia A is reported. The principal objective of this project was to compare the relative merits of coagulation testing and DNA marker analysis in carrier diagnosis for a large unselected haemophilic population. Factor VIII:C (F.VIII:C) and von Willebrand factor antigen (vWf:Ag) were measured on plasma samples sent to a central laboratory. Coagulation results were analysed by a logistic regression model of discrimination. Of 91 potential carriers tested, 15% had indeterminate coagulation test carrier probabilities. Two restriction fragment length polymorphisms were analysed in 123 women (42 obligate carriers and 81 potential carriers). The BcII polymorphism within the F.VIII gene and the locus DXS 52, approximately 5 cM (centimorgan) from F.VIII were used as DNA markers. Of the 81 potential carriers tested with RFLP analysis, a carrier diagnosis was achieved in 52%. Studies with the F.VIII intragenic BgII polymorphism in 23 of these families gave no additional information. Thirty-nine potential carriers remained undiagnosed after DNA marker analysis. Twenty-seven of these women were from families with a sporadic case of haemophilia. In this group of 27 women, 14 were found to have high probability carrier estimates derived from their coagulation tests. Combined coagulation and RFLP data was available in 42 potential carriers. Disagreement between DNA and coagulation carrier diagnoses was found in four instances. In each case, the coagulation data resulted in a carrier probability of indeterminate value. This study emphasizes some of the limitations associated with DNA marker linkage analysis as it pertains to haemophilia A carrier detection. Where a previous family history exists and appropriate females are informative for the DNA markers, this type of analysis is very productive. However, large numbers of potential carriers from 'sporadic' haemophilia families were a factor in this project. With this in mind, an optimal service for haemophilia A carrier diagnosis must continue to offer reliable coagulation test probabilities in addition to DNA marker studies.
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PMID:Carrier detection strategy in haemophilia A: the benefits of combined DNA marker analysis and coagulation testing in sporadic haemophilic families. 290 65

Ninety-one dobermanns have been typed for a polymorphic microsatellite DNA marker situated within an intron of the von Willebrand factor gene and the alleles correlated with von Wille-brand's disease status. Two alleles were identified, one associated only with the normal gene and the other with both normal and disease genes.
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PMID:Von Wille-brand's disease in UK dobermanns: possible correlation of a polymorphic DNA marker with disease status. 884 Feb 49

Linear discriminants that include data on factor VIII:C and von Willebrand factor antigen levels are well-established tools in estimating the probability of carriership in haemophilia A families. A comparison between the conventional coagulation data, i.e. the ratio of factor VIII:C and von Willebrand factor antigen, and the DNA analysis techniques was made in 98 confirmed carriers (39 obligatory, 69 detected by gene tracking analysis) and 71 normal age matched females who did not have any history of bleeding and were not taking any drug. The lowest misclassification rate, i.e. 7% among the carriers, was seen when a cut-off value of 0.7 was chosen. In the case of normals, all were outside this cut-off value. Thus, it was considered as a workable reference value for classifying the carriers in haemophilia A families in our laboratory. We conclude that the optimal service for haemophilia A carrier diagnosis must include above coagulation test probabilities as well as DNA marker studies. However, it is recommended that the smaller laboratories in developing countries can benefit immensely by only establishing factor VIII:C and von Willebrand factor antigen estimation.
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PMID:Carrier detection in haemophilia A families: comparison of conventional coagulation parameters with DNA polymorphism analysis - first report from India. 1046 77

High plasma levels of von Willebrand factor (vWF) have been associated with the risk of thromboembolic disease. As a complex trait, this phenotype must be influenced by genetic and environmental factors. Among the genetic factors, only the ABO gene located on chromosome 9q34 has been clearly linked to the plasma levels of vWF. This locus explains about 30-40% of the genetic variability. Therefore, the source of the majority of the genetic component remains to be identified. To search for these unknown loci, we conducted a genomewide linkage screen for genes affecting normal variation in vWF levels in 21 Spanish families as part of the GAIT (Genetic Analysis of Idiopathic Thrombophilia) Project. The results showed that the strongest linkage signal (LOD =3.46, p = 0.00003) for vWF was found on chromosome 9q34 at the DNA marker D9S290, where the ABO gene is located. Additional suggestive linkage signals were found on chromosomes 2q23.2 (LOD = 1.65, p = 0.003) and 1p36.13 (LOD =1.32, p = 0.007). After refining the linkage analysis, conditional to the ABO genotype, three additional loci on chromosomes 5, 6 and 22 showed LOD scores higher than 1, suggesting the presence of other genes linked to vWF levels. Curiously, no linkage signals were detected in other chromosome regions previously associated with vWF levels (like the structural VWF gene on 12p13.2 or Lewis blood group gene on 19q13). These results indicate that these loci are not important genetic determinants of the normal variation of vWF levels. Our results indicate that the ABO locus is the major genetic determinant of the plasma levels of the vWF in Spanish population. It is possible that there are other potential regions on chromosomes 1, 2, 5, 6 and 22 that influence this thrombosis risk factor. However, the structural vWF gene itself has a very low influence (if any) on the plasma levels of vWF.
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PMID:Genome-wide linkage analysis of von Willebrand factor plasma levels: results from the GAIT project. 1459 95