Haematology and oncology: Glanzmann thrombasthenia: practice question

A General Medicine question in the style of the NEET PG paper. Answer it first, then read why the right option is right and why each of the others is wrong.

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General Medicine · Haematology and oncology: Glanzmann thrombasthenia

Sample item

A child has recurrent mucosal bleeding and easy bruising. The platelet count is normal, bleeding time is prolonged, and PT and aPTT are normal. Platelet aggregation is absent with ADP and collagen but is normal with ristocetin. Which defect is responsible?

ADeficiency of glycoprotein IIb/IIIaBDeficiency of von Willebrand factorCDeficiency of factor VIIIDDeficiency of glycoprotein Ib-IX-V

Original practice item, not a recalled exam question. Nothing here is recorded.

The answer and the reasoning

A. Deficiency of glycoprotein IIb/IIIa

Glanzmann thrombasthenia is an autosomal recessive disorder of platelet glycoprotein IIb/IIIa, which binds fibrinogen, so platelets cannot aggregate with agonists. Ristocetin-induced agglutination, which depends on glycoprotein Ib and von Willebrand factor, is normal. Treatment is platelet transfusion for bleeding.

Option by option

A. Deficiency of glycoprotein IIb/IIIa (correct)
Correct. Absent aggregation to ADP and collagen with normal ristocetin response indicates GPIIb/IIIa deficiency.
B. Deficiency of von Willebrand factor
von Willebrand factor deficiency gives an abnormal ristocetin response and often a prolonged aPTT.
C. Deficiency of factor VIII
Factor VIII deficiency prolongs the aPTT and spares platelet function.
D. Deficiency of glycoprotein Ib-IX-V
Glycoprotein Ib-IX-V deficiency (Bernard-Soulier syndrome) gives giant platelets and absent ristocetin response.

Source note: Original NextPrep sample item — pending expert review. This item is original practice material awaiting independent expert review, so confirm important facts in a standard textbook.

Questions about this General Medicine question

What is the answer to this General Medicine question?

The best answer is A, Deficiency of glycoprotein IIb/IIIa. Glanzmann thrombasthenia is an autosomal recessive disorder of platelet glycoprotein IIb/IIIa, which binds fibrinogen, so platelets cannot aggregate with agonists.

Why is "Deficiency of von Willebrand factor" not the answer?

von Willebrand factor deficiency gives an abnormal ristocetin response and often a prolonged aPTT.

Why is "Deficiency of factor VIII" not the answer?

Factor VIII deficiency prolongs the aPTT and spares platelet function.

Why is "Deficiency of glycoprotein Ib-IX-V" not the answer?

Glycoprotein Ib-IX-V deficiency (Bernard-Soulier syndrome) gives giant platelets and absent ristocetin response.

What concept does this question test?

It tests Haematology and oncology: Glanzmann thrombasthenia in General Medicine. Ristocetin-induced agglutination, which depends on glycoprotein Ib and von Willebrand factor, is normal. Treatment is platelet transfusion for bleeding.

How hard is this question?

We tag it as a multi-step question: it asks you to combine more than one idea. The tag is our own editorial judgement, not an official difficulty rating, so read the reason for every option, not only the answer.

How should I study Haematology and oncology: Glanzmann thrombasthenia?

For each disease know the classic presentation, the best test, and the first-line treatment. Then use the flashcards and the other General Medicine questions on this site to test what stuck.

Is this a real NEET PG question?

No. It is an original practice item (editorial status: sample, version 1). NextPrep does not publish recalled or leaked questions, and independent faculty review of this item has not been completed yet, so confirm important facts in a standard textbook.