Medical genetics: balanced translocation carrier: 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: balanced translocation carrier

Sample item

A couple has had three first-trimester miscarriages. The husband is phenotypically normal, and his karyotype shows 46,XY,t(4;11), a balanced reciprocal translocation. Why do the pregnancies fail?

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

The answer and the reasoning

C. His gametes often carry unbalanced chromosome complements

A balanced translocation carrier is usually healthy, but at meiosis the rearranged chromosomes segregate to give many gametes with partial monosomy or trisomy. Embryos from these gametes often miscarry, so karyotyping is advised in recurrent pregnancy loss.

Option by option

  • A. Each conception has a trisomy due to advanced paternal age

    Trisomies from paternal age are not the mechanism here.

  • B. He is mosaic for a monosomy

    The karyotype shows a balanced translocation, not mosaic monosomy.

  • C. His gametes often carry unbalanced chromosome complements (correct)

    Correct. Segregation produces unbalanced gametes and lethal chromosomal imbalance.

  • D. Imprinting errors arise from the translocation

    Imprinting errors are not the cause of loss in a translocation carrier.

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 C, His gametes often carry unbalanced chromosome complements. A balanced translocation carrier is usually healthy, but at meiosis the rearranged chromosomes segregate to give many gametes with partial monosomy or trisomy.

Why is "Each conception has a trisomy due to advanced paternal age" not the answer?

Trisomies from paternal age are not the mechanism here.

Why is "He is mosaic for a monosomy" not the answer?

The karyotype shows a balanced translocation, not mosaic monosomy.

Why is "Imprinting errors arise from the translocation" not the answer?

Imprinting errors are not the cause of loss in a translocation carrier.

What concept does this question test?

It tests Medical genetics: balanced translocation carrier in Anatomy. Embryos from these gametes often miscarry, so karyotyping is advised in recurrent pregnancy loss.

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: balanced translocation carrier?

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.