Laboratory diagnosis of von Willebrand disease type 1/2E (2A subtype IIE), type 1 Vicenza and mild type 1 caused by mutations in the D3, D4, B1-B3 and C1-C2 domains of the von Willebrand factor gene. Role of von Willebrand factor multimers and the von Willebrand factor propeptide/antigen ratio.
Dominant von Willebrand disease type 2M and 2U are variable expressions of one distinct disease entity caused by loss-of-function mutations in the A1 domain of the von Willebrand factor gene.