Bernard-Soulier syndrome is a hereditary bleeding disorder caused by deficiency or dysfunction of which platelet glycoprotein complex?

• A GPIIb-IIIa (integrin alphaIIb-beta3) — the fibrinogen receptor
• B GPIb-IX-V — the von Willebrand factor receptor ✓
• C GPVI — the collagen receptor
• D Thromboxane A2 receptor (TP receptor)

Explanation

Bernard-Soulier syndrome is caused by mutations in GP1BA, GP1BB, or GP9 encoding subunits of the GPIb-IX-V complex, which is the platelet receptor for von Willebrand factor and mediates initial platelet adhesion to damaged subendothelium. Patients present with mucocutaneous bleeding, giant platelets (macrothrombocytes) on peripheral smear, and absent ristocetin aggregation (ristocetin requires functional GPIb). GPIIb-IIIa deficiency causes Glanzmann thrombasthenia, characterised by absent ADP/collagen/thrombin aggregation with normal ristocetin. GPVI deficiency causes mild bleeding due to impaired collagen-induced activation.

Reference: Robbins & Cotran Pathologic Basis of Disease, 10th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.