IDENTIFICATION OF THE GLYCINE-TO-ARGININE SUBSTITUTION G2043R IN TYPE-VII COLLAGEN IN A FAMILY WITH DOMINANT DYSTROPHIC EPIDERMOLYSIS-BULLOSA FROM HUNGARY

Epidermolysis bullosa (EB) represents a group of genodermatoses charac terized by fragility and easy blistering of the skin. In the dystrophi c forms of EB (DEB), blisters occur below the basement membrane, at th e level of the anchoring fibrils. In the dominantly inherited forms (D DEB), the predominant type of mutation detected thus far is the substi tution of a glycine residue which occurs within the collagenous domain of the molecule characterized by the repeating Gly-X-Y amino acid seq uence. In this study, we searched for mutations in DDEB in a family fr om Hungary, by PCR amplification of segments of COL7A1, followed by he teroduplex analysis. Examination of the PCR fragment corresponding to exon 73 revealed a heteroduplex in affected individuals from the famil y. Sequence analysis revealed a G-to-A transition at nucleotide 6127 i n the triple-helical domain of COL7A1, which converted a glycine resid ue at amino acid position 2043 to an arginine. This report represents the second incidence of this mutation, G2043R, described first in a fa mily with DDEB from Italy.