Systemic paediatrics: Gitelman syndrome: 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.

Try it

Pediatrics · Systemic paediatrics: Gitelman syndrome

Sample item

A 14-year-old has muscle cramps, carpopedal spasm and fatigue. Investigations show hypokalaemia, metabolic alkalosis, hypomagnesaemia and low urinary calcium excretion, with normal blood pressure. Which transporter is defective?

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

The answer and the reasoning

B. Thiazide-sensitive sodium-chloride cotransporter

Gitelman syndrome is an autosomal recessive defect of the thiazide-sensitive NaCl cotransporter in the distal convoluted tubule. It mimics chronic thiazide use, with hypokalaemic alkalosis, hypomagnesaemia and hypocalciuria. Bartter syndrome, by contrast, has hypercalciuria and presents earlier.

Option by option

  • A. Furosemide-sensitive Na-K-2Cl cotransporter

    A defective Na-K-2Cl cotransporter causes Bartter syndrome, with hypercalciuria and earlier presentation.

  • B. Thiazide-sensitive sodium-chloride cotransporter (correct)

    Correct. The thiazide-sensitive cotransporter defect gives hypokalaemic alkalosis, hypomagnesaemia and hypocalciuria.

  • C. Aquaporin-2 water channel

    A defective aquaporin-2 channel causes nephrogenic diabetes insipidus.

  • D. Epithelial sodium channel (ENaC)

    Gain of function of the sodium channel causes Liddle syndrome, with hypertension.

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 Pediatrics questions

Questions about this Pediatrics question

What is the answer to this Pediatrics question?

The best answer is B, Thiazide-sensitive sodium-chloride cotransporter. Gitelman syndrome is an autosomal recessive defect of the thiazide-sensitive NaCl cotransporter in the distal convoluted tubule.

Why is "Furosemide-sensitive Na-K-2Cl cotransporter" not the answer?

A defective Na-K-2Cl cotransporter causes Bartter syndrome, with hypercalciuria and earlier presentation.

Why is "Aquaporin-2 water channel" not the answer?

A defective aquaporin-2 channel causes nephrogenic diabetes insipidus.

Why is "Epithelial sodium channel (ENaC)" not the answer?

Gain of function of the sodium channel causes Liddle syndrome, with hypertension.

What concept does this question test?

It tests Systemic paediatrics: Gitelman syndrome in Pediatrics. It mimics chronic thiazide use, with hypokalaemic alkalosis, hypomagnesaemia and hypocalciuria. Bartter syndrome, by contrast, has hypercalciuria and presents earlier.

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: Gitelman syndrome?

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.