Oral pathology: cysts and odontogenic tumours: BRAF mutation in ameloblastoma: practice question

A Dentistry 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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Dentistry · Oral pathology: cysts and odontogenic tumours: BRAF mutation in ameloblastoma

Sample item

A recurrent conventional ameloblastoma of the mandible is tested for molecular alterations. A MAPK pathway driver that can be targeted with vemurafenib or dabrafenib is found. Which alteration is this?

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

The answer and the reasoning

D. BRAF V600E mutation

BRAF V600E is the commonest driver mutation in conventional mandibular ameloblastoma, activating the MAPK pathway. BRAF inhibitors have produced responses in recurrent or unresectable cases. PTCH1 loss characterises the keratocyst in Gorlin syndrome.

Option by option

  • A. KRAS G12D mutation

    KRAS mutations are not the usual target of vemurafenib or dabrafenib.

  • B. PTCH1 deletion

    PTCH1 deletion is linked to the keratocyst and basal cell carcinoma, not to these drugs.

  • C. KIT D816V mutation

    KIT mutations are seen in gastrointestinal stromal tumours and mastocytosis.

  • D. BRAF V600E mutation (correct)

    Correct. BRAF V600E is common in ameloblastoma and responds to BRAF inhibitors.

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 Dentistry question

What is the answer to this Dentistry question?

The best answer is D, BRAF V600E mutation. BRAF V600E is the commonest driver mutation in conventional mandibular ameloblastoma, activating the MAPK pathway.

Why is "KRAS G12D mutation" not the answer?

KRAS mutations are not the usual target of vemurafenib or dabrafenib.

Why is "PTCH1 deletion" not the answer?

PTCH1 deletion is linked to the keratocyst and basal cell carcinoma, not to these drugs.

Why is "KIT D816V mutation" not the answer?

KIT mutations are seen in gastrointestinal stromal tumours and mastocytosis.

What concept does this question test?

It tests Oral pathology: cysts and odontogenic tumours: BRAF mutation in ameloblastoma in Dentistry. BRAF inhibitors have produced responses in recurrent or unresectable cases. PTCH1 loss characterises the keratocyst in Gorlin syndrome.

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 Oral pathology: cysts and odontogenic tumours: BRAF mutation in ameloblastoma?

Learn the dental formula, eruption ages and tooth structure once, as tables. Then use the flashcards and the other Dentistry 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.