Association of the hemophilia A carrier state and hemorrhagic thrombocytopathy with dilatation of the platelet membrane complex.

Associations of hereditary abnormalities of the factor VIII complex and hereditary platelet disorders have previously been reported in 12 families. Another family is reported in which 6 members had a bleeding tendency and thrombocytopathy characterized by impaired platelet aggregation and dilatation of the platelet membrane complex. Apart from the platelet function abnormalities the proband had diminished levels of factor VIII clotting activity (36 U/dl) and factor VIII clotting antigen (31%) while factor VIII-related antigen and ristocetin cofactor were normal. The other affected family members had normal levels of factor VIII:C. Consequently, the proband was defined as a hemophilia A carrier manifesting also hereditary thrombocytopathy.