Haematology: Bernard-Soulier syndrome: practice question

A Pathology 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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Pathology · Haematology: Bernard-Soulier syndrome

Sample item

A 6-year-old boy has had mucocutaneous bleeding since infancy. Platelet count is 60,000 per microlitre and the film shows giant platelets. Ristocetin-induced aggregation is absent and is not corrected by adding normal plasma, whereas aggregation with ADP and collagen is normal. Which defect is present?

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

The answer and the reasoning

C. Deficiency of platelet glycoprotein Ib-IX-V

Bernard-Soulier syndrome is a defect of the GPIb-IX-V complex, the platelet receptor for von Willebrand factor, so platelet adhesion fails and platelets are large and reduced in number. Ristocetin agglutination is absent and is not corrected by normal plasma because the defect lies in the platelet. In von Willebrand disease the plasma factor is missing and plasma corrects the test.

Option by option

  • A. Deficiency of glycoprotein IIb/IIIa

    A GPIIb/IIIa defect is Glanzmann thrombasthenia, with normal platelet size and normal ristocetin response.

  • B. Defective P2Y12 ADP receptor

    A P2Y12 defect impairs ADP-induced aggregation, which is normal here.

  • C. Deficiency of platelet glycoprotein Ib-IX-V (correct)

    GPIb defect with giant platelets and uncorrectable ristocetin response is Bernard-Soulier syndrome.

  • D. Deficiency of plasma von Willebrand factor

    Plasma von Willebrand factor deficiency would correct the ristocetin test after adding normal plasma.

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 Pathology question

What is the answer to this Pathology question?

The best answer is C, Deficiency of platelet glycoprotein Ib-IX-V. Bernard-Soulier syndrome is a defect of the GPIb-IX-V complex, the platelet receptor for von Willebrand factor, so platelet adhesion fails and platelets are large and reduced in number.

Why is "Deficiency of glycoprotein IIb/IIIa" not the answer?

A GPIIb/IIIa defect is Glanzmann thrombasthenia, with normal platelet size and normal ristocetin response.

Why is "Defective P2Y12 ADP receptor" not the answer?

A P2Y12 defect impairs ADP-induced aggregation, which is normal here.

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

Plasma von Willebrand factor deficiency would correct the ristocetin test after adding normal plasma.

What concept does this question test?

It tests Haematology: Bernard-Soulier syndrome in Pathology. Ristocetin agglutination is absent and is not corrected by normal plasma because the defect lies in the platelet. In von Willebrand disease the plasma factor is missing and plasma corrects the test.

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: Bernard-Soulier syndrome?

Learn each disease as a bundle: cause, key histology, markers, and the clinical hallmark. Then use the flashcards and the other Pathology 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.