Advances in the genetics and treatment of von Willebrand disease.

von Willebrand disease (VWD) is a bleeding disorder caused by quantitative (type 1 and 3) or qualitative (type 2) defects of von Willebrand factor (VWF). The mechanisms of most inherited VWD types have been recently elucidated by genetic and molecular diagnosis, but the phenotypic tests based on measurements of plasma and platelet VWF, the ability of VWF to interact with its platelet receptor, and the analysis of the multimeric composition of VWF are always essential to identify patients with different VWD subtypes. The aim of treatment is to correct the dual defects of hemostasis, ie, abnormal coagulation expressed by low levels of factor VIII (FVIII) and abnormal platelet adhesion expressed by prolonged bleeding time (BT). Desmopressin is the treatment of choice in most patients with type 1 and type 2 VWD, who account for 60 to 70% of cases. In type 3 and in some severe forms of type 1 and type 2 VWD, desmopressin is not effective, and it is necessary to resort to plasma concentrates containing FVIII and VWF. Treated with virucidal methods, these concentrates are effective and currently safe, but they do not always correct the BT defect. Platelet concentrates or desmopressin can be used as adjunctive treatments when poor correction of the BT after concentrates is associated with continued bleeding.