Epidermolysis bullosa simplex with mottled pigmentation: Clinical aspects and confirmation of the P24L mutation in the KRT5 gene in further patients

Epidermolysis bullosa simplex with mottled pigmentation (EBS-MP) is a rare dermatologic disorder of autosomal dominant inheritance with intraepidermal blistering after minor trauma, reticular hyperpigmentation unrelated to th e blistering, nail dystrophy, and mild palmoplantar keratosis. Keratin 5 an d keratin 14 are known to be essential for the basal keratinocyte cytoskele ton and are defective in several forms of epidermolysis bullosa simplex. Re cently, a 71C-->T transition in the keratin 5 gene (KRT5) causing a P24L su bstitution was identified in some patients with EBS-MP. We present a family with three affected members and a sporadic patient with EBS-MP. They exemp lify clinically mild expression with intrafamilial variability and the poss ibility of improvement with time. In all of them, mutation analysis of the KRT5 gene showed the P24L mutation. So far, other mutations in the same or in other genes have not been reported in patients with EBS-MP. Am. J. Med. Genet. 86:376-379, 1999. (C) 1999 Wiley-Liss, Inc.