Von Willebrand disease (VWD) is the most common autosomally inherited bleeding disorder characterized by abnormal quantity or quality of von Willebrand factor (VWF). Type 1 VWD exhibits a mild to moderate reduction in functionally normal VWF; type 2 VWD involves the expression of functionally abnormal VWF (further subdivided into types 2A, 2B, 2M, and 2N); and type 3 VWD presents the virtually complete absence of VWF. Clinical symptoms of VWD include predominantly mild mucosal bleeding. Joint bleeding can occur in the most severe forms.
