Embryology: caudal regression: 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 · Embryology: caudal regression

Sample item

A newborn of a mother with poorly controlled pregestational diabetes has sacral agenesis, hypoplastic lower limbs and absent lower lumbosacral vertebrae. What is the diagnosis?

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

The answer and the reasoning

A. Caudal regression syndrome

Maternal diabetes is a recognised cause of caudal regression, in which caudal mesoderm fails to develop. The result is sacral and lumbar vertebral agenesis with lower limb hypoplasia and neurogenic bladder.

Option by option

  • A. Caudal regression syndrome (correct)

    Correct. Absent sacral and lumbar vertebrae with small legs in a diabetic pregnancy defines this syndrome.

  • B. Sacrococcygeal teratoma

    A sacrococcygeal teratoma is a tumour mass arising from remnants of the primitive streak.

  • C. Prune belly syndrome

    Prune belly syndrome shows abdominal wall muscle deficiency with undescended testes and urinary tract dilatation.

  • D. Spina bifida occulta

    Spina bifida occulta is a vertebral arch defect without absent vertebrae or limb hypoplasia.

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.

More Anatomy questions

Questions about this Anatomy question

What is the answer to this Anatomy question?

The best answer is A, Caudal regression syndrome. Maternal diabetes is a recognised cause of caudal regression, in which caudal mesoderm fails to develop.

Why is "Sacrococcygeal teratoma" not the answer?

A sacrococcygeal teratoma is a tumour mass arising from remnants of the primitive streak.

Why is "Prune belly syndrome" not the answer?

Prune belly syndrome shows abdominal wall muscle deficiency with undescended testes and urinary tract dilatation.

Why is "Spina bifida occulta" not the answer?

Spina bifida occulta is a vertebral arch defect without absent vertebrae or limb hypoplasia.

What concept does this question test?

It tests Embryology: caudal regression in Anatomy. The result is sacral and lumbar vertebral agenesis with lower limb hypoplasia and neurogenic bladder.

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 Embryology: caudal regression?

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.