A family of type IIE von Willebrand's disease. The first reported case in Japan.

We have described two family members with type II E von Willebrand's disease (vWD). The propositus exhibited moderate bleeding tendency. Hemostatic screening tests revealed prolonged Ivy bleeding time with normal platelet counts, decreased vWF: Ag and vWF: RCo and normal VIII: C. Analysis of vWF multimeric structure by SDS-agarose gel electrophoresis showed markedly decreased large multimer and abnormal structure of each multimer. Using long gel, multimeric structure was further characterized. There was only one prominent band seen, located in the center of each multimer. Four satellite bands, usually seen in normal vWF were missing or markedly decreased. Subunit composition of vWF was also analysed by SDS polyacrylamide gel electrophoresis and anti-vWF monoclonal antibody immunoblotting. In contrast to normal vWF, 176kD and 140kD fragments were hardly detectable in patient's vWF. DDAVP infusion at the dosage of 0.4μg/kg resulted in shortening of bleeding time and slightly increase in vWF: Ag and vWF: RCo.This represents the first case of type II E vWD reported in Japan.