This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Pathology
Glanzmann's thrombasthenia is characterized by defective 
Select and explain. 
A. Gp IB/IX, B. Gp IIB/IIIA, C. Gp IB/IIIA, D. Gp IIB/IX
B: Gp IIB/IIIA
Answer: B: Gp IIB/IIIA 
Explanation: Glanzmann's thrombasthenia - It is an autosomal recessive disorder due to deficiency/dysfunction of glycoprotein Ilb-IIla (Gp Ilb/IIIa).
Thus there is defective platelet aggregation.
Platelet aggregation is normal to ristocetin(ln constant to Bernard Soulier syndrome) but no aggregation occurs in response to standard agonists (collagen, A DP, thrombin). Other differentiating features include normal platelet count and morphology. BT is prolonged. VWF is normal.
The disease manifests at birth with increased bleeding from umbilical cord stump.