Dominant Dystrophic Epidermolysis Bullosa: Mutation Analysis

Dominant Dystrophic Epidermolysis Bullosa: Mutation AnalysisHereditary epidermolysis bullosa is a group of single gene genodermatoses, which are characteristic of blister because of injuring skin or mucosa. According to the location of bullosa, it was divided into epidermolysis bullosa simplex (EBS), junctional epidermolysis bullosa (JEB) and dystrophic epidermolysis bullosa (DEB).Dystrophic epidermolysis bullosa (DEB) is caused by mutations in the COL7A1 gene encoding type â…¦ collagen, the major components of anchoring fibrils. The characteristic genetic lesion is a glycine substitution in the dominant DEB (DDEB) in the collagenous domain of the protein. In this study, we identified a Chinese family with a four-generation pedigree of DDEB, in whom a novel glycine substitution mutation in COL7A1 was demonstrated. A nucleotide G-to-A transition at position 6208 in exon 74 of COL7A1 was detected, which resulted in a glycine to an arginine (G2070R) in the triple-helical domain of type â…¦ collagen. This substitution was not found in 110 unrelated normal alleles.This report emphasizes the predominance of glycine substitution mutations in DDEB and contributes to the expanding database on COL7A1 mutations. This study should be useful for genetic counseling and prenatal diagnosis for the family and expands the database of mutations underlying DDEB. Elucidation of the nature of pathogenic mutation has implications for the relevance of future gene therapy strategies.