Which type of von Willebrand disease is autosomal recessive and most severe?

Which type of von Willebrand disease is autosomal recessive and most severe?

• A. Type 1
• B. Type 2A
• C. Type 2B
• D. Type 3

Answer: (D)

Understanding how inheritance and VWF levels affect bleeding helps explain why this is the most severe form. Von Willebrand factor promotes platelet adhesion and stabilizes factor VIII in the circulation. When VWF is almost completely absent, as in this form, platelet plug formation is severely compromised and factor VIII activity drops markedly. The result is heavy, often mucosal, bleeding that begins in childhood and can be quite severe. This form is inherited in an autosomal recessive manner, meaning two defective copies are typically needed for the full-blown disease. Other types involve either milder quantitative deficiencies (where some VWF is present) or qualitative defects in VWF that alter its function, and most of these follow autosomal dominant patterns with milder or more variable bleeding. Therefore, the combination of autosomal recessive inheritance and near-complete absence of VWF makes this type the most severe.

Understanding how inheritance and VWF levels affect bleeding helps explain why this is the most severe form. Von Willebrand factor promotes platelet adhesion and stabilizes factor VIII in the circulation. When VWF is almost completely absent, as in this form, platelet plug formation is severely compromised and factor VIII activity drops markedly. The result is heavy, often mucosal, bleeding that begins in childhood and can be quite severe. This form is inherited in an autosomal recessive manner, meaning two defective copies are typically needed for the full-blown disease.

Other types involve either milder quantitative deficiencies (where some VWF is present) or qualitative defects in VWF that alter its function, and most of these follow autosomal dominant patterns with milder or more variable bleeding. Therefore, the combination of autosomal recessive inheritance and near-complete absence of VWF makes this type the most severe.