Systemic paediatrics: Glanzmann thrombasthenia: practice question

A Pediatrics 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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Pediatrics · Systemic paediatrics: Glanzmann thrombasthenia

Sample item

A 3-year-old has had recurrent epistaxis and gum bleeding since infancy. Platelet count, PT and aPTT are normal. Platelet aggregation is absent with ADP, collagen and epinephrine but normal with ristocetin. Which defect is responsible?

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

The answer and the reasoning

D. Deficient glycoprotein IIb/IIIa

Glanzmann thrombasthenia is an autosomal recessive qualitative platelet defect of the integrin GPIIb/IIIa, which binds fibrinogen, so platelets do not aggregate to physiological agonists although they agglutinate with ristocetin. The platelet count is normal. Treatment is platelet transfusion and antifibrinolytics, with recombinant factor VIIa for refractory bleeding.

Option by option

  • A. Deficient factor VIII

    Factor VIII deficiency prolongs aPTT and does not impair platelet aggregation.

  • B. Deficient glycoprotein Ib-IX-V

    GPIb-IX-V deficiency is Bernard-Soulier syndrome, with no ristocetin response and giant platelets.

  • C. Deficient von Willebrand factor

    Von Willebrand factor deficiency reduces the ristocetin response and may prolong aPTT, but it is not an aggregation defect to ADP.

  • D. Deficient glycoprotein IIb/IIIa (correct)

    Correct. GPIIb/IIIa deficiency abolishes aggregation but spares 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.

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Questions about this Pediatrics question

What is the answer to this Pediatrics question?

The best answer is D, Deficient glycoprotein IIb/IIIa. Glanzmann thrombasthenia is an autosomal recessive qualitative platelet defect of the integrin GPIIb/IIIa, which binds fibrinogen, so platelets do not aggregate to physiological agonists although they agglutinate with ristocetin.

Why is "Deficient factor VIII" not the answer?

Factor VIII deficiency prolongs aPTT and does not impair platelet aggregation.

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

GPIb-IX-V deficiency is Bernard-Soulier syndrome, with no ristocetin response and giant platelets.

Why is "Deficient von Willebrand factor" not the answer?

Von Willebrand factor deficiency reduces the ristocetin response and may prolong aPTT, but it is not an aggregation defect to ADP.

What concept does this question test?

It tests Systemic paediatrics: Glanzmann thrombasthenia in Pediatrics. The platelet count is normal. Treatment is platelet transfusion and antifibrinolytics, with recombinant factor VIIa for refractory 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 Systemic paediatrics: Glanzmann thrombasthenia?

Memorise milestones and the vaccine schedule as tables and revise them often. Then use the flashcards and the other Pediatrics 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.