Incontinentia pigmenti (Bloch-Sulzberger syndrome) has all of the following features EXCEPT:

• A X-linked dominant inheritance lethal in males
• B Stage III lesions are hyperpigmented whorled macules following Blaschko's lines
• C Caused by mutation in NEMO/IKKgamma gene
• D Nail dystrophy occurs in stage IV (atrophic stage) ✓

Explanation

Nail changes (subungual keratotic tumors) in incontinentia pigmenti occur in a subset of cases and are not specifically confined to stage IV. Stage IV is the atrophic/hypopigmented stage. The four stages are: I — vesicular/bullous with eosinophilia; II — verrucous/keratotic; III — hyperpigmented whorled macules along Blaschko lines; IV — atrophic hypopigmented streaks. The NEMO/IKKgamma gene mutation is correct. X-linked dominant lethal in hemizygous males is correct; surviving affected males usually have Klinefelter mosaicism.

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.