[XbaI polymorphism in intron 22 of factor VIII and gene potential for prenatal diagnosis of hemophilia A].

Polymorphism of an XbaI restriction endonuclease site in intron 22 of the factor VIII gene was studied. 79 heredity-unrelated X chromosomes from 83 Chinese were analyzed. The frequency of the polymorphic site was 0.56, providing polymorphism information content (PIC) of 0.49. Fourteen out of 17 families with hemophilia A could be diagnosed by the Xba 1/22i restricted fragment length polymorphism (RFLPs). Therefore, as a genetic marker within the factor VIII gene, Xba I/22i RFLPs should be useful for prenatal diagnosis of hemophilia A and for detection of its carriers.