Question:medium
Bernard-Soulier syndrome is due to deficiency of
Bernard-Soulier syndrome is due to deficiency of
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Bernard-Soulier is an adhesion defect; identify the platelet receptor for von Willebrand factor.
Updated On: Jun 23, 2026
- Gp 2b/3a
- Gp 1b
- vWf
- TNF
Show Solution
The Correct Option is B
Solution and Explanation
Step 1: Frame this as a question about platelet adhesion versus aggregation. Bernard-Soulier syndrome is an inherited disorder where platelets cannot stick to the damaged vessel wall, so we are looking for the missing adhesion receptor.
Step 2: Platelet adhesion to the injured subendothelium depends on von Willebrand factor acting as a bridge. The platelet side of that bridge is the glycoprotein $Gp1b$ (the $Gp1b$-$IX$-$V$ complex). In BSS this receptor is deficient, so the vWF bridge has nothing to anchor to.
Step 3: A useful contrast: when the missing piece is the aggregation receptor $Gp2b/3a$ instead, the disease is Glanzmann thrombasthenia. When the missing piece is vWF itself, the disease is von Willebrand disease. BSS is specifically the loss of the $Gp1b$ receptor.
Step 4: TNF is an inflammatory cytokine, completely unrelated to platelet receptor biology, so it is discarded.
Hence Bernard-Soulier syndrome results from deficiency of Gp 1b.\[\boxed{\text{Gp 1b}}\]
Step 2: Platelet adhesion to the injured subendothelium depends on von Willebrand factor acting as a bridge. The platelet side of that bridge is the glycoprotein $Gp1b$ (the $Gp1b$-$IX$-$V$ complex). In BSS this receptor is deficient, so the vWF bridge has nothing to anchor to.
Step 3: A useful contrast: when the missing piece is the aggregation receptor $Gp2b/3a$ instead, the disease is Glanzmann thrombasthenia. When the missing piece is vWF itself, the disease is von Willebrand disease. BSS is specifically the loss of the $Gp1b$ receptor.
Step 4: TNF is an inflammatory cytokine, completely unrelated to platelet receptor biology, so it is discarded.
Hence Bernard-Soulier syndrome results from deficiency of Gp 1b.\[\boxed{\text{Gp 1b}}\]
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