The novel mutation in the COL7A1 gene in the patient with dystrophic forms of epidermolysis bullosa

Abstract

Dystrophic Epidermolysis Bullosa (DEB) is a rare inherited blistering disorder with both autosomal recessive (RDEB) and autosomal dominant (DDEB) mode of inheritance. DEB is characterized by affected dermis-epidermis conjunction, which results from COL7A1 mutations. COL7A1 encodes collagen VII, the major component of anchoring fibrils (AF), which is responsible for dermis-epidermis conjunction. Structural modification of AFs or significant alterations in its numbers could result in DEB. In the current investigation, patients within six families affected by DEB underwent complete clinical evaluation. Moreover, the causative mutations were identified in the COL7A1 gene by next generation sequencing and then confirmed by Sanger sequencing. A pathogenic homozygous and heterozygous glycine substitution mutation were identified in exon 54 of twin siblings of the family I (c.5018G > A, p.G1673E). In family II, a frameshift deletion mutation in exon 75 was identified in a 7-year-old patient (c.6265delC, p.P2090fs). A novel pathogenic frameshift insertion mutation was confirmed in a 6-year-old girl (c.179-180insGAAA, p.F60fs) in family III. These findings expand scientific knowledge of the EB causative mutations, which facilitates the EB classification and lead to more accurate prenatal diagnosis in the families at the high risk of such diseases.