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 the 
blistering, nail dystrophy, and mild palmoplantar keratosis. Keratin 5 and 
keratin 14 are known to be essential for the basal keratinocyte cytoskeleton and 
are defective in several forms of epidermolysis bullosa simplex. Recently, a 
71C-->T transition in the keratin 5 gene (KRT5) causing a P24L substitution was 
identified in some patients with EBS-MP. We present a family with three affected 
members and a sporadic patient with EBS-MP. They exemplify clinically mild 
expression with intrafamilial variability and the possibility 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.