What is von Willebrand Disease (VWD)?
Von Willebrand disease (VWD – also known as von Willebrand disorder) is an inherited bleeding disorder. People with VWD have a problem with a protein in their blood called von Willebrand factor (VWF) that helps control bleeding. They do not have enough of the protein or it does not work the way it should. It takes longer for blood to clot and for bleeding to stop.
How common is VWD?
VWD is the most common inherited bleeding disorder worldwide. It affects both males and females from all racial backgrounds.
Most people with VWD are born with the disorder as VWD is inherited genetically. Sometimes VWD will show up when the person is a child. Others don’t find out until they are adults and have a bleeding problem, or until a relative is diagnosed and it is suggested that they are tested as well.
Many people with VWD may not know they have the disorder because bleeding symptoms for most people with VWD are very mild. VWD can also be difficult to diagnose accurately and testing and diagnosis needs to be done by specialists with experience in VWD. More than 2,500 people have been diagnosed with VWD in Australia, but research suggests that many others are not yet diagnosed.
In comparison to the number of people with VWD with the mild form, the form causing moderate bleeding problems is uncommon, and the severe form of VWD is rare.
However, it is important to remember that there can be bleeding problems with all forms of VWD and any bleeding that occurs with VWD needs to be assessed and treated.
Types
There are three main types of von Willebrand disease. Bleeding symptoms can vary from person to person within each type.
- Type 1 VWD is the most common form. Around 80% of all people with VWD have this form. In type 1 VWD, the von Willebrand Factor (VWF) works normally, but there is not enough of it. Symptoms are usually mild, depending on the level of VWF in the blood. However, some people with type 1 can have very low levels of VWF and have severe bleeding problems.
- Type 2 VWD is divided into subtypes 2A, 2B, 2M and 2N. Certain subtypes may be treated differently, which makes knowing the exact type of VWD you have very important. In type 2 VWD, the amount of VWF in people’s blood is often normal but the VWF doesn’t work properly.
- Type 3 VWD is very rare. People with type 3 VWD have very little or no VWF in their blood. Bleeding can occur more often, be more severe and can also include joint and muscle bleeding.