[Indirect methods in the genetic diagnosis of hemophilia A].

In haemophilia A (HA), besides the direct detection of the most common mutation of the factor VIII gene (the gene inversion), it was necessary to establish indirect methods which are suitable to reveal the pattern of inheritance of the genes examined, regardless of the mutations they carry. This task can be achieved by the analysis of DNA polymorphisms located within and in the near proximity of the factor VIII gene. For diagnostic purposes we used an RFLP and two microsatellite polymorphisms. The aim of our program is to provide carrier and also prenatal diagnostics for affected families. So far we completed the analyses of 15 HA patients and 68 of their family members, and we gave prenatal diagnoses in 3 cases. According to the information content of the polymorphisms used, we expect to be able to provide DNA diagnoses to 95% of the Hungarian HA families requesting the test.