von Willebrand Disease, Type 2M

**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 shows decreased platelet adhesion without a deficiency of high molecular weight multimers; this functional defect is caused by mutations that disrupt VWF binding to platelets or to subendothelium.