MBTPS2 and keratosis follicularis spinulosa decalvans: MBTPS2 missense mutations were previously identified in the related dermatological conditions IFAP/BRESHECK (ichthyosis follicularis, atrichia, and photophobia, OMIM #308205)7, 8 and keratosis follicularis spinulosa decalvans (KFSD, X-linked, OMIM #308800)9.