von Willebrand Disease, Type 2A

**Semantic type:** Disease or Syndrome

**Definition:** An autosomally inherited (generally dominant) coagulation disorder characterized by qualitative abnormalities of the von Willebrand factor (VWF). The mutant VWF causes decreased platelet adhesion due to a selective deficiency of high molecular weight multimers. The decrease in large multimers can be due to a failure to synthesize the multimers ('group 1') or enhanced ADAMTS13-mediated proteolysis of the secreted high molecular weight protein ('group 2').