A mutation in the V1 domain of keratin 5 causes epidermolysis bullosa simplex with mottled pigmentation.

Epidermolysis bullosa simplex with mottled pigmentation (EBS-MP; MIM no 131960) is an autosomal dominant disorder characterized by skin blistering at acral sites, punctate palmo-plantar hyperkeratoses, and mottled pigmentation of the trunk and proximal extremities. Histologically and ultrastructurally, the blistering in EBS-MP closely resembles that found in other EBS subtypes. This is consistent with a disorder of the basal keratinocyte cytoskeleton, in which several groups have found disease-causing mutations within the central rod domains of keratins 5 and 14. We have identified a C --> T transition at base position 71 of K5 causing a P24L substitution in a sporadic case of EBS-MP. Recently, this same mutation was identified in two unrelated families with EBS-MP.