Glanzmann's thrombasthenia is characterized by defective: (A) Gp IB/IX, (B) Gp IIB/IIIA, (C) Gp IB/IIIA, (D) Gp IIB/IX
Answer is B. 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.