[The prenatal diagnosis of hemophilia A--the use of PCR and family RFLP analysis].

Seven families with hemophilia A were analyzed by using the polymerase chain reaction (PCR) technique. Prenatal diagnosis was performed in 4 cases at high risk of hemophilia A. The results suggested that the gene fragment of factor VIII might be amplified by the simple, fast and sensitive PCR technique and is especially suited to prenatal diagnosis using very small amounts of chorionic villi or amniocytes. Restriction fragment length polymorphism (RFLPs) analysis of BclI was also performed. The sample, which could not be diagnosed by BclI, could be analyzed with RFLPs of XbaI. Finally, DNA probe's Southern blotting analysis could be used for those samples which could not be diagnosed with XbaI. 85% of all hemophilia A cases could be diagnosed with our technique.