Virology: precore mutant hepatitis B: practice question

A Microbiology 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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Microbiology · Virology: precore mutant hepatitis B

Sample item

A man with chronic hepatitis B has persistently raised ALT. HBsAg is positive, HBeAg is negative, anti-HBe is positive and HBV DNA is markedly raised. Which explanation fits best?

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

The answer and the reasoning

D. A precore stop-codon mutant that cannot synthesise HBeAg

In the precore mutant, a stop codon prevents HBeAg production while the virus keeps replicating. The result is HBeAg-negative chronic hepatitis with high DNA and active inflammation, and it needs antiviral therapy.

Option by option

  • A. Co-infection with hepatitis D suppressing HBeAg

    Hepatitis D requires HBsAg but does not explain the HBeAg-negative high-replication pattern.

  • B. Inactive carrier state with minimal replication

    An inactive carrier has low viral load and normal ALT.

  • C. Resolved infection with immunity

    Resolved infection would be HBsAg negative with anti-HBs.

  • D. A precore stop-codon mutant that cannot synthesise HBeAg (correct)

    Correct. HBeAg-negative disease with high viral load and raised ALT suggests a precore mutant.

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 Microbiology question

What is the answer to this Microbiology question?

The best answer is D, A precore stop-codon mutant that cannot synthesise HBeAg. In the precore mutant, a stop codon prevents HBeAg production while the virus keeps replicating.

Why is "Co-infection with hepatitis D suppressing HBeAg" not the answer?

Hepatitis D requires HBsAg but does not explain the HBeAg-negative high-replication pattern.

Why is "Inactive carrier state with minimal replication" not the answer?

An inactive carrier has low viral load and normal ALT.

Why is "Resolved infection with immunity" not the answer?

Resolved infection would be HBsAg negative with anti-HBs.

What concept does this question test?

It tests Virology: precore mutant hepatitis B in Microbiology. The result is HBeAg-negative chronic hepatitis with high DNA and active inflammation, and it needs antiviral therapy.

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 Virology: precore mutant hepatitis B?

Make a one-line identity card for each organism: shape and stain, defining test, toxin, disease and drug. Then use the flashcards and the other Microbiology 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.