[Occurrence of hemophilia A and von Willebrand disease in the same family].

Occurrence of the two congenital hemorrhagic disorders, von Willebrand disease (vWD) and hemophilia A, was found in the same family. The propositus was a 21-year-old male patient with findings of moderate hemophilia A. Father, the eldest sister and second eldest sister were found to have mild type I vWD. Mother was confirmed to be a hemophilia A carrier, and the eldest son of second eldest sister to be a moderate hemophilia A. These results suggest that the occurrence of the two hemorrhagic disorders may have been resulted from the incidental mating of father's vWD gene and mother's hemophilia A gene, and suggest that second eldest sister may be the double heterozygosity of type I vWD and hemophilia A.