Medical genetics: Fanconi anaemia: practice question

A Anatomy 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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Anatomy · Medical genetics: Fanconi anaemia

Sample item

A 6-year-old with short stature, absent radii, cafe-au-lait spots and pancytopenia is suspected of an inherited marrow failure. Which test confirms the diagnosis?

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

The answer and the reasoning

D. Chromosomal breakage test with a DNA cross-linking agent

Fanconi anaemia is an autosomal recessive DNA cross-link repair disorder. Lymphocytes show excessive chromosomal breakage after exposure to diepoxybutane or mitomycin C.

Option by option

  • A. Flow cytometry for CD55 and CD59

    CD55 and CD59 flow cytometry diagnoses paroxysmal nocturnal haemoglobinuria.

  • B. Bone marrow trephine biopsy

    A marrow biopsy shows hypocellularity but does not identify the cause.

  • C. Haemoglobin electrophoresis

    Haemoglobin electrophoresis diagnoses haemoglobinopathies.

  • D. Chromosomal breakage test with a DNA cross-linking agent (correct)

    Correct. Increased breakage with cross-linking agents confirms Fanconi anaemia.

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 Anatomy question

What is the answer to this Anatomy question?

The best answer is D, Chromosomal breakage test with a DNA cross-linking agent. Fanconi anaemia is an autosomal recessive DNA cross-link repair disorder.

Why is "Flow cytometry for CD55 and CD59" not the answer?

CD55 and CD59 flow cytometry diagnoses paroxysmal nocturnal haemoglobinuria.

Why is "Bone marrow trephine biopsy" not the answer?

A marrow biopsy shows hypocellularity but does not identify the cause.

Why is "Haemoglobin electrophoresis" not the answer?

Haemoglobin electrophoresis diagnoses haemoglobinopathies.

What concept does this question test?

It tests Medical genetics: Fanconi anaemia in Anatomy. Lymphocytes show excessive chromosomal breakage after exposure to diepoxybutane or mitomycin C.

How hard is this question?

We tag it as an application question: it asks you to use a fact on a patient or a finding. 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 Medical genetics: Fanconi anaemia?

Learn every nerve by its route, its muscles and what a lesion looks like at the bedside. That one habit answers a large share of questions. Then use the flashcards and the other Anatomy 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.