Bernard-Soulier syndrome in two Swedish families: effect of DDAVP on bleeding time.

We present 2 patients with Bernard-Soulier syndrome from two different families. The parents of one of the patients were found to have had common ancestors in the 17th century. The platelet membrane content of glycoprotein (GP)Ib was measured in the patients and their first-degree relatives with an ELISA technique based on monoclonal antibodies. Both patients had very low levels of GPIb. In one of the families the heterozygotes had reduced expression of GPIb but in the other the obligate heterozygotes had normal values, suggesting that the molecular pathology differs between the two families. In both patients, bleeding time was shortened by infusion of DDAVP (1-deamino-8-D-arginine vasopressin), although it was not completely normalised. DDAVP may be of some therapeutic value in cases of Bernard-Soulier syndrome.