Von Willebrand Disease affects males and females equally. However, because symptoms can be mild, many people affected have not been diagnosed. People with VWD have decreased or malfunctioning Von Willebrand factor (VWF) activity and therefore cannot form a proper platelet plug.
- VWF is the protein that makes platelets stick together to form a platelet plug.
- VWF is a carrier protein for factor VIII. VWF ensures that there is enough factor VIII in the blood stream, t carries it to the site of injury, and protects it from being broken down in the blood stream.
Types of Von Willebrand Disease:
- Type 1 – von Willebrand levels are lower than normal
- Type 2 – there is a defect in the structure of the von Willebrand protein that causes lower than normal VW factor protein activity.
- Type 2a – the level of VW factor is reduced, as is the ability of platelete to clump together
- Type 2b – although the VW factor is defective, the ability for platelets to clump together is actually increased.
- Type 2m – the VWF is not able to stick to the platelets and therefore a platelet plug is not properly formed.
- Type 2n – Also called type 2 Normandy. Type 2n occurs when there isn’t enough VWF to carry the factor VIII protein to the site of injury and therefore there are decreased levels of factor VIII to form a fibrin clot.
- Type 3 – there is very little or no von Willebrand protein produced at all.
Severity of Von Willebrand Disease:
Bleeding can be mild, moderate or severe within each type of vWD. The severity depends in part on the level of VW factor activity. Blood type plays a role in the levels of VW factor found in the blood. Type O blood often has lower levels of VW factor.
|Type of vWD||Severity|
|Type I||Symptoms are usually mild.|
|Type II||Symptoms are usually moderate.|
|Type III||Symptoms are usually severe|
|Severe hemophilia||Less than 1%|
Symptoms of Von Willebrand Disease:
- Nose bleeds
- Prolonged bleeding from minor cuts
- Heavy of longer than usual menstrual bleeding
- Blood in the urine
- Blood in the stools
- Large bruises
- Gums bleed easily
- Heavy periods and/or periods lasting more than 7 days