Genodermatoses: Papillon-Lefevre syndrome: practice question

A Dermatology 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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Dermatology · Genodermatoses: Papillon-Lefevre syndrome

Sample item

A child has thick red-yellow keratoderma of palms and soles and has lost primary teeth early because of severe periodontitis. Which gene is mutated?

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

The answer and the reasoning

C. Cathepsin C

Papillon-Lefevre syndrome is an autosomal recessive palmoplantar keratoderma with severe early periodontitis caused by cathepsin C (CTSC) mutations. Retinoids and dental care are used. Keratin 9 mutations cause epidermolytic palmoplantar keratoderma.

Option by option

  • A. Keratin 9

    Keratin 9 mutation causes epidermolytic palmoplantar keratoderma without periodontitis.

  • B. Loricrin

    Loricrin mutation causes Vohwinkel variant keratoderma.

  • C. Cathepsin C (correct)

    Correct. Cathepsin C mutation causes Papillon-Lefevre syndrome.

  • D. Connexin 26

    Connexin 26 mutation causes deafness with keratoderma.

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 Dermatology question

What is the answer to this Dermatology question?

The best answer is C, Cathepsin C. Papillon-Lefevre syndrome is an autosomal recessive palmoplantar keratoderma with severe early periodontitis caused by cathepsin C (CTSC) mutations.

Why is "Keratin 9" not the answer?

Keratin 9 mutation causes epidermolytic palmoplantar keratoderma without periodontitis.

Why is "Loricrin" not the answer?

Loricrin mutation causes Vohwinkel variant keratoderma.

Why is "Connexin 26" not the answer?

Connexin 26 mutation causes deafness with keratoderma.

What concept does this question test?

It tests Genodermatoses: Papillon-Lefevre syndrome in Dermatology. Retinoids and dental care are used. Keratin 9 mutations cause epidermolytic palmoplantar keratoderma.

How hard is this question?

We tag it as an application question: it asks you to use a fact on a patient or a finding. 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 Genodermatoses: Papillon-Lefevre syndrome?

Learn each condition by its primary lesion, site and signature sign. Then use the flashcards and the other Dermatology 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.