This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Haematology, Subject name: Pathology
Bernard Soulier syndrome is due to defect in 
Select and explain. 
A. GP IB/IX, B. GP IIB/IIIa, C. Fibrinogen, D. vWF
A: GP IB/IX
Answer: A: GP IB/IX 
Explanation: Bernard-Soulier syndrome (BSS), is a rare autosomal recessive bleeding disorder that causes a deficiency of glycoprotein Ib(GpIb), the receptor for von Willebrand factor Causes Mutations in GP1BA, GP1BB and GP9 Diagnostic method Flow cytometry analysis Treatment Platelet transfusion