Enfermedad de von Willebrand en la IX Region de Chile.

Bleeding disorders are frequent indications for reference to Hematologic Clinics. Won Willebrand's disease (vWD) is one of the commonest of inheritable hemorrhagic diathesis. In order to evaluate the frequency and clinical characteristics of vWD in the IX Region of Chile, we performed a clinical and laboratory investigation in 132 patients, children and adults, over a period of 3 years: 1983-1985. Within this group there was 26 close relatives. The laboratory tests used for the diagnosis were: bleeding time, factor VIII, von Willebrand factor and ristocetin cofactor. Diagnosis of vWD was made in 83 cases, most of them presenting the mild form of the disease. Two children had the severe form. The estimated prevalence of vWD in symptomatic patients in the IX Region of Chile is at least 113 per million, which makes it 3 or 4 times more frequent than hemophilia. vWD is observed at a much lower rate in mapuche than in caucasian population. The symptoms and their frequency were: post partum bleeding 75%, dental extraction bleeding 65%, surgical bleeding 65%, epistaxis 63%, menorrhagia 54%, easy bruising 45%, deep hematomas 8% and petechiae 5%. Five cases were asymptomatic. The bleeding time was the test most frequently abnormal: 72/83 cases (87%).