Von Willebrand Disease is divided into three main types, with a fourth type being acquired vWD, which is not hereditary. Learn more about these three main types:
Type 1 – About 85% of people diagnosed with vWD have type 1, the mildest form. People with type 1 have lower than normal von Willebrand factor in their blood.
Type 2 – About 20% of those diagnosed with vWD have type 2. This type has a normal amount of vW factor in their blood, but it does not function as it should. There are four subtypes of Type 2: A, B, M, and N.
Type 2A occurs when the vW factor multimers are not the right size, which prevents the platelets from making a suitable platelet plug.
Type 2B occurs when the vW factor multimers are not the right size and cause the vW factor to become overactive.
Type 2M occurs when the vW factor cannot cling to the platelets preventing a suitable platelet plug from forming.
Type 2N occurs when the vW factor cannot perform its job as the carrier and protector of another factor in the blood, factor VIII. Sometimes this bleeding disorder is confused with or misdiagnosed as hemophilia, but it is not because the issue is with the von Willebrand factor, not factor VIII. This subtype is sometimes referred to as Type 2 Normandy, which is attributed to patients first diagnosed with this subtype in the Normandy region in France.
Type 3 – Only 3% of those diagnosed with vWD have type 3. This type has little-to-no vW factor in their blood, increasing their risk for severe bleeding into joints.