Novel COL7A1 Gene Mutations Responsible For Bart’s Syndrome:Report Of A Chinese Family

Background:Bart’s syndrome was initially described as a genodermatosis. It is characterized by congenital localized absence of the skin, togethering with blistering and nail abnormalities. It has been demonstrated that ultrastructural abnormalities in the anchoring fibrils and linkage of the inheritance of the disease to the region of chromosome 3 near the type VII collagen gene (COL7A1). We studied a three-generation family with an autosomal dominant history and perform mutation analysis.Objective:To identify gene mutations in the affected individuals of the family.Methods:A family containing four affected individuals and 20 volunteers participated in the study. Careful physical examination was performed on the affected infant, followed by evaluation of his family members’detailed medical history and physical examination. Then a biopsy was performed on the infant’s father in order to diagnose the disease. Genomic DNA was extracted by salting-out method from the blood of the family members and 20 healthy volunteers in the control group. DNA specimens were subjected to mutation analysis by polymerase chain reaction (PCR) amplification of all exons and flanking sequences of COL7A1, and subsequent sequence of the PCR products.Results:Four mutant alleles were disclosed for this family. Direct sequencing of the PCR product demonstrated a heterozygous C>G transition at nucleotide position 6 within exon 1, a A>G transition at position 107 within exon 21 and a G>A transition at position 103 within exon 73 of COL7A1, which resulted in a aspartic acid to glutamic acid (Asp2Glu), a glutamine to arginine (Gln36Arg) and a glycine to arginine (Gly35Arg) substitution. Nevertheless, there is also a nonsense mutation (OT) at position 58 within exon 108. No evidence of mutations in any other genes was obtained.Conclusion:There are gene mutations of COL7A1 in the affected individuals of the family.