Type 2 von Willebrand Disease (type 2 VWD) is characterized by a bleeding disorder associated with deficiency of Von Willebrand factor (VWF) as well as its functional anomalies. This type accounts for 20-45% of all cases of VWD. There are four subtypes of type 2 VWD known as; types 2A, 2B, 2M and 2N. Three of these subtypes are associated with anomalies in the interaction of VWF with platelets and/or the subendothelium. Type 2A is caused by VWF multimerization anomalies. Type 2B occurs due to increased VWF affinity for platelets. Type 2M occurs due to decreased VWF affinity for platelets. Type 2N occurs due to decreased VWF affinity for factor VIII (FVIII). Types 2A, 2B and 2M are characterized by mucocutaneous manifestations. Patients with type 2N experience less spontaneous abnormal bleeding events than in the other forms of type 2 VWD.
Preventative or curative treatment includes substitution therapy with purified human VWF.