Squamous cell carcinoma in a family with dominant dystrophic epidermolysis bullosa: A molecular genetic study

Squamous cell carcinoma (SCC) is a frequent complication in the severe, recessively inherited forms of dystrophic epidermolysis bullosa (RDEB), however, only rarely reported in dominant DEB. Although the SCCs in RDEB are frequently well-differentiated by histopathology, they often have a poor prognosis due to multicentricity, rapid invasiveness, and development of distant metastases. In this study, we sought to determine the molecular basis of DDEB in a family with the unusual occurrence of SCCs. Specifically, a large DDEB family with 2 individuals being affected with SCC was analyzed for potential mutations in the type VII collagen gene (COL7A1) by heteroduplex scanning and direct nucleotide sequencing of PCR amplified segments of the gene. This mutation detection strategy disclosed a G→A transition at nucleotide position 6,235 which resulted in substitution of a glycine by arginine within the collagenous region of COL7A1. This study establishes, for the first time, the molecular basis in a family with DDEB/SCC. Clinically, this study reemphasizes the importance of vigilance in surveying DEB patients, not only those with recessive but also with dominant inheritance, for SCC.