Characterization of patients with dystrophic epidermolysis bullosa for collagen VII therapy

Funding sources: National Institutes of Health/National Institute of Arthritis and Musculoskeletal and Skin Diseases (Grant # R01 AR055914), California Institute for Regenerative Medicine (Grant # DR1‐01454), Office of Research and Development, Palo Alto VA Medical Center, Epidermolysis Bullosa Medical Research Foundation, National Institutes of Health/National Center for Research Resources (Grant # UL1 RR025744). Conflicts of interest: none declared. Dear Editor, Dystrophic epidermolysis bullosa (DEB) is a blistering skin disease caused by mutations in the gene (COL7A1) encoding type VII collagen (C7). DEB can be inherited by either dominant (DDEB) or recessive (RDEB) mechanisms. RDEB results in severe wounds and scarring, and extracutaneous manifestations such as oesophageal strictures, chronic anaemia and pseudosyndactyly. DDEB is generally a milder form of the disease, with fewer and less severe blisters.1 COL7A1 contains 118 exons. The central Gly‐X‐Y region is flanked by two noncollagenous (NC) regions: the amino‐terminal NC1 domain (exons 1–28) and the carboxyl‐terminal NC2 domain (exons 112–118). Patients with RDEB may either express the NC1 amino‐terminal fragment of C7 (NC1+) or lack it (NC1−).2 The NC1 region has been reported to contain the major antigenic epitopes of C7, although immune responses to other C7 regions have been noted.3 In the autoimmune disease epidermolysis bullosa acquisita, IgG autoantibodies bind to various epitopes in C7, causing dermoepidermal separation and blistering.3