A glycine-to-arginine substitution in the triple-helical domain of type VII collagen in a family with dominant dystrophic epidermolysis bullosa pruriginosa.

Epidermolysis bullosa pruriginosa is a recently recognized variant of dystrophic epidermolysis bullosa (DEB) characterized by severe pruritus and scarring, mainly involving the extensors of the extremities. In this study, we searched for mutations in the type VII collagen gene (COL7A1) using polymerase chain reaction amplification of exonic segments of COL7A1, followed by heteroduplex analysis, in a Chinese pedigree with dominant DEB displaying a striking anastomosing network of lichenoid papules and scarring. The study revealed a G-to-A transition at nucleotide 6724 within exon 85 of COL7A1, converting a glycine to an arginine (G2242R) within the triple-helical domain of the type VII collagen in affected individuals. These findings demonstrate that EB pruriginosa in this family is a clinical variant of dominant DEB.