VWD is caused by either a deficiency of VWF or having VWF that malfunctions. VWD is usually genetically inherited. However, it can also be acquired or caused by a spontaneous mutation in the gene that carries the instructions to produce VWF. Pseudo-VWD is inherited or is caused by a spontaneous mutation. A family history is common, but you can have VWD with no known family history (especially since some individuals with VWD have mild to no symptoms and are never diagnosed).
Symptoms and Diagnosis of VWD
If you have VWD, you will likely bleed more often and for longer than someone who does not have a bleeding disorder. Anyone with any type of VWD can have the following symptoms:
- Easy bruising
- Mucocutaneous bleeding
- Bleeding from the nose and gums
- Prolonged bleeding from cuts
- Menorrhagia (heavy or prolonged menstrual bleeding: longer than 5 days, more than 90 ml of bleeding, and/or clots larger than a grape)
- Bleeding may occur after surgery or when you have a tooth pulled
- Blood in the urine
- Blood in the stools
- Joint and muscle bleeds (usually VWD type 3)
- Gastrointestinal bleeding (usually VWD type 2A and aVWS)
Diagnosing VWD can be a complex process. Those who have milder VWD (usually VWD type 1 and VWD type 2) might not have any issues until later in life when a major injury or surgery occurs. Because VWD type 3 is so severe, diagnosis often occurs in infancy. Diagnosis also occurs earlier if there is a family history. Because VWF and FVIII levels shift with hormone changes, women especially should be screened more than once. For women, the best day to have your blood drawn and tested is on the first day of your menstrual cycle.
In addition to a bleeding history, a coagulation study to diagnose VWD might include the following:
- FVIII coagulant activity
- Total blood count (assessing hemoglobin, hematocrit, platelet count [PC] and morphology, prothrombin time [PT], and activated partial thromboplastin time [aPTT])
- ABO blood group (those who have VWD and blood type O may have worse symptoms)
- Fibrinogen level
- thrombin time (TT)
- VWD profile testing
- VWF:Ag (plasma levels of VWF)
- VWF:RCo (function of VWF protein)
- FVIII:C (ability of VWF to carry FVIII)
- VWF multimer analysis
- VWF:FVIIIB (specifically to diagnose VWD type 2n)
- RIPA (primarily to diagnose VWD type 2b, but may be an indicator for VWD type 3)
- Genetic testing (especially useful in differentiating VWD type 2n from hemophilia A)
- Platelet function analysis
Note: Thrombin time, prothrombin time, platelet counts, fibrinogen levels, hemoglobin levels, hematocrit levels and aPTT may be normal even if a patient has VWD.
Severity of VWD
VWD can be mild, moderate, or severe; however, severity is also tied to VWD type and blood type (because those with type O blood often have lower VWF levels). While there is an exception to every rule, in general, Types 1 and 2 VWD and pseudo-VWD tend to be mild or moderate. Type 3 VWD is severe. aVWS can range from mild to severe.