Mutations of COL7A1 gene in three cases of dystrophic epidermolysis bullosa pruriginosa / 中华皮肤科杂志

ABSTRACT

Objective To detect the mutations of COL7A1 gene in three cases of dystrophic epidermolysis bullosa pruriginosa (DEBP). Methods Clinical data were collected from 3 patients with DEBP. Skin lesions were obtained from these patients and subjected to transmission electron microscopy. DNA was extracted from the peripheral blood of the 3 patients, their 16 relatives, and 150 unrelated normal human controls, and PCR was performed to amplify all the exons and flanking sequences of COL7A1 gene followed by sequencing.Results The patient 1 and 2 had family history, whereas the case 3 was sporadic. Transmission electron microscopy showed tissue cleavage beneath lamina densa in case 1 and slightly decreased anchoring fibrils in some areas of the lesions in case 1 and 3. Three heterozygous mutations of COL7A1 gene, i.e., c. G6734T, c.G6859A and c. G5318T, which leaded to three amino acid mutations, i.e., p. G2245V, p. G1773V and p. G2287R, were found in patient 1, 2 and 3 respectively. Of them, p. G2245V and p. G1773V were novel mutations. The mutations strictly cosegregated with the phenotype in the patients of family 1 and 2. No mutation was detected in the unaffected parents of patient 3 or the 150 unrelated healthy controls. Conclusions The p. G2245V, p. G2287Rand p. G1773V mutations of COL7A1 gene may be responsible for the phenotype of DEBP in the three cases,and of them, p. G2245V and p. G1773V have never been reported.