Gastroenterology and hepatology: abetalipoproteinaemia: practice question

A General Medicine 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

General Medicine · Gastroenterology and hepatology: abetalipoproteinaemia

Sample item

A 3-year-old child has steatorrhoea and failure to thrive. A blood film shows acanthocytes, serum cholesterol is very low, and chylomicrons and LDL are absent. Later he develops ataxia and retinitis pigmentosa. Which defect is responsible?

ALipoprotein lipase deficiencyBLDL receptor deficiencyCPancreatic lipase deficiencyDMicrosomal triglyceride transfer protein deficiency

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

The answer and the reasoning

D. Microsomal triglyceride transfer protein deficiency

Without microsomal triglyceride transfer protein, apolipoprotein B-containing lipoproteins cannot be assembled, so fat is trapped in enterocytes and absorption of fat and fat-soluble vitamins fails. Vitamin E deficiency causes the neurological and retinal features, and acanthocytes appear on the film.

Option by option

A. Lipoprotein lipase deficiency
Lipoprotein lipase deficiency causes very high triglycerides and chylomicronaemia, not low lipids.
B. LDL receptor deficiency
LDL receptor deficiency causes high LDL cholesterol, not low.
C. Pancreatic lipase deficiency
Pancreatic lipase deficiency causes steatorrhoea but not acanthocytes or low cholesterol.
D. Microsomal triglyceride transfer protein deficiency (correct)
Correct. Failure to assemble chylomicrons and LDL explains the lipid profile and vitamin E deficiency.

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.

Questions about this General Medicine question

What is the answer to this General Medicine question?

The best answer is D, Microsomal triglyceride transfer protein deficiency. Without microsomal triglyceride transfer protein, apolipoprotein B-containing lipoproteins cannot be assembled, so fat is trapped in enterocytes and absorption of fat and fat-soluble vitamins fails.

Why is "Lipoprotein lipase deficiency" not the answer?

Lipoprotein lipase deficiency causes very high triglycerides and chylomicronaemia, not low lipids.

Why is "LDL receptor deficiency" not the answer?

LDL receptor deficiency causes high LDL cholesterol, not low.

Why is "Pancreatic lipase deficiency" not the answer?

Pancreatic lipase deficiency causes steatorrhoea but not acanthocytes or low cholesterol.

What concept does this question test?

It tests Gastroenterology and hepatology: abetalipoproteinaemia in General Medicine. Vitamin E deficiency causes the neurological and retinal features, and acanthocytes appear on the film.

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 Gastroenterology and hepatology: abetalipoproteinaemia?

For each disease know the classic presentation, the best test, and the first-line treatment. Then use the flashcards and the other General Medicine 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.