Toxicology: amatoxin mushroom poisoning: practice question

A Forensic 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

Forensic Medicine · Toxicology: amatoxin mushroom poisoning

Sample item

A family eats wild mushrooms and 10 hours later develops severe vomiting and watery diarrhoea. They improve at 24 hours but on day 3 develop jaundice and coagulopathy. What is the mechanism of toxicity?

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

The answer and the reasoning

A. Inhibition of RNA polymerase II by amatoxin, causing hepatocyte necrosis

Amanita phalloides contains amatoxins, which inhibit RNA polymerase II and halt protein synthesis, particularly in the liver. The typical course is delayed gastrointestinal illness after 6 to 24 hours, an apparent recovery, and then hepatic failure on days 2 to 4. Treatment includes supportive care, silibinin or N-acetylcysteine and transplantation in fulminant failure.

Option by option

  • A. Inhibition of RNA polymerase II by amatoxin, causing hepatocyte necrosis (correct)

    Correct. Amatoxins block RNA polymerase II and injure hepatocytes.

  • B. Inhibition of acetylcholinesterase by muscarine

    Muscarine mushrooms cause early cholinergic features within an hour or two.

  • C. Binding of the toxin to sodium channels causing paralysis

    Paralysis from sodium channel toxins does not fit this delayed hepatic course.

  • D. Blockade of GABA receptors by muscimol

    Muscimol mushrooms cause early confusion and delirium, not delayed liver failure.

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 Forensic Medicine questions

Questions about this Forensic Medicine question

What is the answer to this Forensic Medicine question?

The best answer is A, Inhibition of RNA polymerase II by amatoxin, causing hepatocyte necrosis. Amanita phalloides contains amatoxins, which inhibit RNA polymerase II and halt protein synthesis, particularly in the liver.

Why is "Inhibition of acetylcholinesterase by muscarine" not the answer?

Muscarine mushrooms cause early cholinergic features within an hour or two.

Why is "Binding of the toxin to sodium channels causing paralysis" not the answer?

Paralysis from sodium channel toxins does not fit this delayed hepatic course.

Why is "Blockade of GABA receptors by muscimol" not the answer?

Muscimol mushrooms cause early confusion and delirium, not delayed liver failure.

What concept does this question test?

It tests Toxicology: amatoxin mushroom poisoning in Forensic Medicine. The typical course is delayed gastrointestinal illness after 6 to 24 hours, an apparent recovery, and then hepatic failure on days 2 to 4. Treatment includes supportive care, silibinin or N-acetylcysteine and transplantation in fulminant failure.

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 Toxicology: amatoxin mushroom poisoning?

Learn postmortem changes with their timelines, and toxicology as poison, sign, test and antidote. Then use the flashcards and the other Forensic 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.