A newborn is encased in a tight, shiny, plate-like membrane that cracks at flexures. After shedding, the child develops widespread ichthyosis. Mutation in TGM1 gene (encoding transglutaminase 1) is identified. The diagnosis is:

• A Harlequin ichthyosis
• B Lamellar ichthyosis ✓
• C X-linked ichthyosis
• D Epidermolytic ichthyosis (bullous CIE)

Explanation

Lamellar ichthyosis is an autosomal recessive disorder most commonly caused by TGM1 mutations (transglutaminase 1, essential for cornified envelope formation). The collodion baby presentation is classic — a tight membranous shell that restricts movement and breathing. After shedding, patients have large brown plate-like scales. X-linked ichthyosis is due to steroid sulfatase deficiency. Harlequin ichthyosis is due to ABCA12 mutation. Epidermolytic ichthyosis is due to keratin 1/10 mutations.

Reference: Neena Khanna Illustrated Synopsis of Dermatology & STD, 6th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.