Genodermatoses: harlequin ichthyosis: 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.

Try it

Dermatology · Genodermatoses: harlequin ichthyosis

Sample item

A newborn is born with thick, plate-like armour scales with fissures, ectropion and eclabium. Which gene is defective?

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

The answer and the reasoning

C. ABCA12

Harlequin ichthyosis is an autosomal recessive disorder caused by ABCA12 mutations that impair lipid transport into the stratum corneum. Neonates need intensive care with emollients, and early oral retinoids improve survival.

Option by option

  • A. TGM1 only

    TGM1 mutation causes the usual lamellar ichthyosis and collodion baby.

  • B. KRT14

    KRT14 mutation causes epidermolysis bullosa simplex.

  • C. ABCA12 (correct)

    Correct. ABCA12 mutation causes harlequin ichthyosis.

  • D. COL7A1

    COL7A1 mutation causes dystrophic epidermolysis bullosa.

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 Dermatology questions

Questions about this Dermatology question

What is the answer to this Dermatology question?

The best answer is C, ABCA12. Harlequin ichthyosis is an autosomal recessive disorder caused by ABCA12 mutations that impair lipid transport into the stratum corneum.

Why is "TGM1 only" not the answer?

TGM1 mutation causes the usual lamellar ichthyosis and collodion baby.

Why is "KRT14" not the answer?

KRT14 mutation causes epidermolysis bullosa simplex.

Why is "COL7A1" not the answer?

COL7A1 mutation causes dystrophic epidermolysis bullosa.

What concept does this question test?

It tests Genodermatoses: harlequin ichthyosis in Dermatology. Neonates need intensive care with emollients, and early oral retinoids improve survival.

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 Genodermatoses: harlequin ichthyosis?

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.