An infant presents with generalized erythroderma and fine scaling along with severe atopic dermatitis unresponsive to standard treatment. Hair examination reveals nodes along the shafts that give them a bamboo appearance under light microscopy. The defective gene encodes:

• A Keratin 1
• B LEKTI (serine protease inhibitor) ✓
• C Connexin 26
• D Lorcrin (loricrin)

Explanation

Netherton syndrome is an autosomal recessive disorder caused by SPINK5 mutations, which encode LEKTI, a serine protease inhibitor regulating corneodesmosin degradation. The triad comprises ichthyosis linearis circumflexa, trichorrhexis invaginata (bamboo hair), and atopic diathesis with markedly elevated IgE. Keratin 1 mutation causes epidermolytic ichthyosis, connexin 26 relates to keratitis-ichthyosis-deafness syndrome, and loricrin mutations cause Vohwinkel syndrome with honeycomb palmoplantar keratoderma.

Reference: Rook's Textbook of Dermatology, 9th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.