[Use of molecular and genetic approaches in prenatal diagnosis and prevention of hemophilia A and Duchenne muscular dystrophy].

Allele polymorphism has been evaluated using blot hybridization and a polymerase cascade of DNA synthesis in 40 families at high risk of hemophilia A (a total of 147 subjects) and in 15 families with Duchenne's myodystrophy, Heterozygous carriage of hemophilia A was identified or confirmed in 18 and ruled out in 4 close female relatives of probands. Prenatal tests for fetal hemophilia A were performed in 5 women from families with hemophilia A (in the 1st trimester in 2 and in the 2nd trimester in 3). Four diagnoses of hemophilia A were confirmed and 1 was ruled out. The DNA methods proved revealing in 34 of 40 families with hemophilia A and in 11 of 15 families with Duchenne's myodystrophy. Three of 9 probands were found to have a deletion of the proximal gene for Duchenne's myodystrophy in the DNA probe area of XY 1.1. Prospects of screening for heterozygous carriage and prenatal identification of hemophilia A and Duchenne's myodystrophy are discussed.