We have developed a new method of screening for hemophilia A in families at risk for the disease. A DNA probe (St 14) that detects a very polymorphic region on the human X chromosome has been shown to be closely linked to hemophilia A. We observed no recombination between the St 14 locus and hemophila, A in 12 families studied. The odds in favor of linkage are 4.4 x 109 to 1 (lod score, 9.65). The 95 per cent confidence interval for the probability of a recombination between St 14 and hemophilia A is 0 to 6.5 per cent. This DNA probe, which is informative in more than 90 per cent of families at risk of hemophilia A, can be used in conjunction with classic biologic assays to identify carriers with an accuracy of 96 per cent or more. If a small risk of misclassification due to crossover between the test and the disease loci is accepted, this DNA marker should allow first-trimester prenatal diagnosis of hemophilia A. Segregation analysis with St 14 may thus represent a major improvement in genetic counseling for hemophilia A.
|Number of pages||5|
|Journal||New England Journal of Medicine|
|Publication status||Published - 1985|
ASJC Scopus subject areas