A novel mutation in the helix termination peptide of keratin 5 causing epidermolysis bullosa simplex Dowling-Meara

Epidermolysis bullosa simplex Dowling-Meara (MIM# 1317600) is the most severe of the three common epidermolysis bullosa simplex subtypes. In addition to the palmoplantar distribution seen in other epidermolysis bullosa simplex subtypes, extensive herpetiform blistering spontaneously develops on the trunk and limbs and may lead to scarring or milia formation. The keratin 5 and keratin 14 genes encode proteins that form the primary structural components of the basal epidermal keratinocytes, mutations in either of these genes can cause epidermolysis bullosa simplex. In this study we sequenced these genes in a family with epidermolysis bullosa simplex Dowling-Meara. We report a novel T to C transition in the helix termination peptide of K5 that causes a nonconservative substitution of a highly conserved amino acid within this critical region (I466T). This mutation adds to those previously reported and provides further evidence of phenotype-genotype correlation in epidermolysis bullosa simplex.