What do we learn from dystrophic epidermolysis bullosa, nails only? Idiopathic nail dystrophy may harbor a COL7A1 mutation as the underlying cause.

Dystrophic epidermolysis bullosa (DEB) is a genodermatosis caused by mutations in the COL7A1 gene. DEB, nails only (DEB-na), is a rare type of DEB. Patients with DEB-na can be overlooked, and genetic testing is helpful to determine the correct diagnosis. We collected two families with DEB-na. Clinical information was analyzed. Ultrastructural analysis of the skin tissue was performed. Blood samples were obtained. Next-generation sequencing was performed and the results were confirmed by Sanger sequencing. A genetic study revealed two novel heterozygous mutations: COL7A1:c.6742G>A (p.G2248R) in patient 1 and c.7181C>G (p.P2394R) in patient 2. Precise diagnosis was made for every patient based on clinical findings and genetic studies. We summarized the phenotype and COL7A1 mutations related to DEB-na. We report a new phenotype of DEB-na and two novel mutations in COL7A1. In addition, we emphasize the importance of careful clinical examination and genetic testing in the diagnosis of DEB-na.