What is von Willebrand Disease?

• A. The most common inherited bleeding disorder, characterized by a deficiency of von Willebrand factor
• B. A deficiency of factor VIII only
• C. A deficiency of factor IX only
• D. An excess of von Willebrand factor

Answer: (A)

Von Willebrand disease is the most common inherited bleeding disorder, caused by a deficiency or dysfunction of von Willebrand factor. This factor is key for helping platelets adhere to damaged blood vessels and for stabilizing factor VIII in circulation. When VWF is reduced or defective, bleeding tends to be mucocutaneous (nosebleeds, easy bruising, gum bleeding) and is often detected by a prolonged bleeding time, with potential effects on factor VIII levels. That’s why the statement describing it as the most common inherited bleeding disorder and noting a deficiency of von Willebrand factor is the best description.

This isn’t describing a deficiency of factor VIII or IX alone, which would point to hemophilia A or B, a different bleeding disorder. And having an excess of von Willebrand factor would not cause the bleeding seen in von Willebrand disease; it would more likely be associated with a tendency toward clotting rather than bleeding.