Question

Which is not true?

• A. vWD type 1 is mostly severe ds in children
• B. vWD type 3 mostly severe ds in children
• C. vWD type 2 is more related activity rather than levels
• D. vWD type 3 has severely low VWD

Hint:

Type 1 vWD is the commonest and mildest form — any statement calling it "severe" is the false one.

Answer 1

The Correct Option is A

Step 1: Background on von Willebrand Disease (vWD). vWD is the most common inherited bleeding disorder, caused by a quantitative or qualitative defect in von Willebrand factor (vWF). vWF mediates platelet adhesion to subendothelium and carries factor VIII. It is classified into Type 1 (partial quantitative deficiency), Type 2 (qualitative defect - vWF is functionally abnormal), and Type 3 (near-complete quantitative deficiency / severe).

Step 2: Evaluate the statement that is NOT true. Option A says "vWD type 1 is mostly severe disease in children" - this is FALSE. Type 1 is the most common form (~75% of cases) and is characteristically a mild disorder with a partial reduction in vWF; it usually presents with mild mucocutaneous bleeding, not severe disease. Therefore option A is the incorrect (false) statement, which is what the question asks for.

Step 3: Why the other statements are TRUE (so not the answer). Option B - Type 3 is the most severe form, with virtually absent vWF, and presents in childhood with severe bleeding; TRUE. Option C - Type 2 is a qualitative/functional defect, so vWF activity (ristocetin cofactor activity) is reduced disproportionately to the vWF antigen level, i.e. it relates more to activity than to absolute levels; TRUE. Option D - Type 3 has severely low vWF (essentially absent) and consequently very low factor VIII; TRUE.

Final answer: Option A - the statement that Type 1 vWD is mostly severe disease in children is NOT true.