Dystrophic epidermolysis bullosa is an inherited bullous dermatosis caused by COL7A1 gene mutation in autosomal dominant or recessive mode.COL7A1 gene encodes type Ⅶ collagen--the main component of the anchoring fibrils at dermal-epidermal junction.Besides the 730 mutations reported in COL7A1 gene,we identified two novel mutations in a Chinese family,which caused recessive dystrophic epidermolysis bullosa(RDEB).The diagnosis was established histopathologically and ultrastructurally.After genomic DNA extraction from the peripheral blood sample of all subjects(5 pedigree members and 136 unrelated control individuals),COL7A1 gene screening was performed by polymerase chain reaction amplification and direct DNA sequencing of the whole coding exons and flanking intronic regions.Genetic analysis of COL7A1 gene in affected individuals revealed compound heterozygotes with identical novel mutations.The maternal mutation is 2-bp deletion at exon 8 of COL7A1 gene (c.1006_1007delCA),leading to a subsequent reading frame-shift and producing a premature termination codon located 48 amino acids downstream in exon 9(p.Q336EfsX48),consequently resulting in truncation of 2562 amino acids downstream.This was only present in two affected brothers,but not in all other unaffected family members.The paternal mutation is a 1-bp deletion occurring at the first base of intron 65(c.IVS5568+1 delG)that deductively changes the strongly conserved GT dinucleotide at the 5donor splice site of exon 65,results in subsequent reading-through into intron 65 and creates a stop codon immediately following the amino acids encoded by exon 65(GTAA→TAA).This is predicted to produce a truncated protein lacking of 1089 C-terminal amino acids downstream.This was found in all family members except one of two unaffected sisters.Both of the two mutations were observed concurrently only in two brother patients.Neither one was found in 136 unrelated Chinese control individuals.This study reveals novel disease-causing mutations in COL7A1 gene.