A 28-year-old woman presents with heavy menstrual bleeding and easy bruising since childhood. Bleeding time is prolonged, platelet count is normal, aPTT is mildly prolonged, and VWF antigen is reduced at 25%. Ristocetin cofactor activity is 15%. Factor VIII activity is 30%. Which type of von Willebrand disease is most likely?
- A Type 2B (gain-of-function with increased binding to GPIb)
- B Type 2A (loss of high-molecular-weight multimers)
- C Type 1 (partial quantitative deficiency) ✓
- D Type 3 (complete deficiency)
Correct answer: C. Type 1 (partial quantitative deficiency)
Explanation
Type 1 VWD is the most common (70-80% of cases) and shows proportional reduction in VWF antigen, ristocetin cofactor activity, and factor VIII (VWF stabilizes FVIII). Levels are typically 20-50% of normal. Type 2 shows a qualitative defect with disproportionate activity-to-antigen ratio (ristocetin cofactor activity << VWF antigen). Type 3 shows near-complete absence (<5%). The preserved ratio here supports type 1.
Reference: Hoffbrand's Postgraduate Haematology, 7th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.