Lamellar ichthyosis (autosomal recessive congenital ichthyosis) presents at birth as a 'collodion baby'. The gene most commonly mutated in the classic lamellar subtype encodes:

• A Transglutaminase-1 (TGM1) ✓
• B Filaggrin (FLG)
• C Keratin-1 (KRT1)
• D Claudin-1 (CLDN1)

Explanation

Mutations in TGM1 (transglutaminase-1) are the most common genetic cause of lamellar ichthyosis, accounting for approximately 30–50% of cases. Transglutaminase-1 crosslinks cornified envelope proteins; its deficiency disrupts the lipid barrier of the stratum corneum, leading to the characteristic large, dark plate-like scales covering the entire body with minimal erythema. Filaggrin mutations cause ichthyosis vulgaris (the most common form, but autosomal dominant); Keratin-1/10 mutations cause epidermolytic ichthyosis; CLDN1 mutations cause NISCH syndrome.

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.