A de novo glycine substitution mutation in the collagenous domain of COL7A1 in dominant dystrophic epidermolysis bullosa

Dystrophic epidermolysis bullosa (DEB) is a hereditary mechanobullous disor der characterized by fragility of the skin and mucous membrane due to abnor malities of anchoring fibrils, Both dominant and recessive DEB have been sh own to be caused by mutations in COL7A1, the gene encoding type VII collage n which is the major component of anchoring fibrils, De novo mutation in do minant DEB is rare, In this study, we report a novel de novo glycine substi tution mutation in COL7A1 in a Chinese Female patient presenting with mild DEB, In search of the mutation, we scanned the entire COL7A1 using polymera se chain reaction (PCR) amplification of all exons of COL7A1, followed by h eteroduplex analysis and direct sequencing of the PCR products that exhibit ed heteroduplex pattern, A G-to-A transition at nucleotide position 6082 wi thin exon 73 of COL7A1 was detected, The mutation converted a glycine to an arginine (G2028R) within the triple-helical domain of type VII collagen, I t was confirmed that the mutation was present only in the proband. Haplotyp e analyses suggested that the case arose as a de novo occurrence of autosom al dominant DEB.