There are three main types of von Willebrand disease (VWD), which are labeled type 1, type 2, and type 3. Which type a patient has depends on the amount of a protein called von Willebrand factor (VWF) in his or her blood as well as its ability to function properly. The type of VWD guides treatment decisions, so determining the correct type of VWD is very important.
Type 1
Type 1 VWD is the mildest and most common form of VWD, characterized by low levels of VWF. About 70% to 80% of people with VWD have type 1.
Type 2
Type 2 VWD is distinguished by VWF that does not function properly even if levels are sufficient. About 15 to 30% of people with the disease have type 2 VWD.
Type 2 VWD is broken into four subtypes:
- Type 2A is marked by insufficient levels of normal multimers of VWF.
- Type 2B occurs when VWF binds too tightly to platelets, possibly causing thrombocytopenia, a low number of platelets in the blood.
- Type 2M, in contrast to type 2B, is characterized by VWF that does not bind tightly enough to platelets.
- Type 2N is characterized by VWF that does not bond properly to factor VIII.
Type 3
Type 3 VWD is characterized by an absence of VWF. Type 3 VWD is the most serious form of the disease; fortunately it is very rare.
Last Updated:
6/26/2009 9:43 PM