von Willebrand disease (VWD), can be divided into three major types(1):
- Type 1 is characterized by partial quantitative deficiency of functionally normal VWF and type 3 with a complete absence.
- Type 2 VWD is characterized by a qualitatively defective VWF, which results into an asymmetric decrease in VWF activity and VWF antigen (VWF:Ag).
- Type 2 VWD is subdivided into 2A, 2B, 2M, and 2N based on the specific functional defect(s). A fourth type, acquired VWD, is not hereditary. This type of VWD in adults results after a diagnosis of an autoimmune disease, or from heart disease or some types of cancer. It can also be due to underlying medical disorder.
People with VWD experience frequent nosebleeds, easy bruising, and excessive bleeding during and after invasive procedures, such as tooth extractions and surgery. Women often experience heavy menstrual bleeding (heavy menstrual periods that last longer than average) and haemorrhaging after childbirth.
The choice of an appropriate therapy depends on VWD subtyping and severity.