OBJECTIVE: To perform gene mutation analysis in a Chinese pedigree with dystrophic epidermolysis bullosa pruriginosa (DEB-Pr), and explore phetotype, genotype, and genotypes-phenotypes relationship of DEB-Pr. METHODS: Potential variants of the COL7A1 gene were detected by skin targeted sequencing panel and verified by Sanger sequencing. The pathogenicity of the variation was analyzed. RESULTS: Compound heterozygous variants, c.4128delT and c.8234G>A, were detected in the COL7A1 gene of the two patients. The c.4128delT(p.Pro1376fs) variant was derived from their mother and unreported previously. According to the American College of Medical Genetics and Genomics Standards and Guidelines, it was suggested to be a pathogenic mutation. The c.8234G>A(p.Arg2745Gln) variant was derived from their father, and possibly is a pathogenic variation. CONCLUSION In this study, the compound heterozygous variants of c.4128delT(p.Pro1376fs) and c.8234G>A(p.Arg2745Gln) of the COL7A1 gene probably underlies the disease in this patient and his sister. And our study expands the database on mutations of DEB-Pr.
Collagen Type VII/genetics* ; Epidermolysis Bullosa Dystrophica/genetics* ; Female ; Humans ; Male ; Mutation ; Pedigree ; Phenotype

Epidermolysis bullosa (EB) is a group of clinically and genetically heterogeneous diseases characterized by trauma-induced mucocutaneous fragility and blister formation. Here, we investigated five Chinese families with EB, and eight variants including a novel nonsense variant (c.47G>A, p.W16*) in LAMA3, a known recurrent variant (c.74C>T, p.P25L) in KRT5, 2 novel (c.2531T>A, p.V844E; c.6811_6814del, p.R2271fs) and 4 known (c.6187C>T, p.R2063W; c.7097G>A, p.G2366D; c.8569G>T, p.E2857*; c.3625_3635del, p.S1209fs) variants in COL7A1 were detected. Notably, this study identified a nonsense variant in LAMA3 that causes EB within the Chinese population and revealed that this variant resulted in a reduction in LAMA3 mRNA and protein expression levels by nonsense-mediated mRNA decay. Our study expands the mutation spectra of Chinese patients with EB.
Humans ; Asian People/genetics* ; China ; Collagen Type VII/genetics* ; Epidermolysis Bullosa/genetics* ; Epidermolysis Bullosa Dystrophica/genetics* ; Keratin-5/genetics* ; Mutation ; Pedigree ; Laminin/genetics*

OBJECTIVE: To carry out genetic testing and prenatal diagnosis for a family affected with recessive dystrophic epidermolysis bullosa (RDEB). METHODS: All exons of the COL7A1 gene and their flanking regions were subjected to PCR and Sanger sequencing. Suspected variant was validated in family members, based on which prenatal diagnosis was provided. RESULTS: Sanger sequencing found that the proband has carried two variants of the COL7A1 gene, namely c.7289delC (p.Pro2430Glnfs*36) and c.7474C>T (p.Arg2492*), which were respectively derived from his mother and father. The same variants were not found among 100 healthy controls. By prenatal diagnosis, the fetus was found to have inherited the c.7474C>T (p.Arg2492*) variant from its father. CONCLUSION The pathogenic variants of the COL7A1 gene of the RDEB family were clarified, based on which prenatal diagnosis was provided.
Child ; Collagen Type VII ; genetics ; Epidermolysis Bullosa Dystrophica ; genetics ; Exons ; Female ; Genes, Recessive ; Genetic Testing ; Humans ; Male ; Mutation ; Pregnancy ; Prenatal Diagnosis ; Sequence Analysis, DNA

Dystrophic epidermolysis bullosa (DEB) are caused by mutations in the COL7A1 gene, which encodes type VII collagen. Even though more than 500 different COL7A1 mutations have been identified in DEB, it still remains to be under-investigated. To investigate the mutation of COL7A1 in moderately severe phenotype of recessive DEB (RDEB) in a Korean patient, the mutation detection strategy was consisted of polymerase chain reaction (PCR) amplification of genomic DNA, followed by heteroduplex analysis, nucleotide sequencing of the PCR products demonstrating altered mobility. In this study, we found that one mutation (c.8569G>T) was detected within exon 116. The mutation of c.8569G>T in exon 116 changed the GAG (Glu) to TAG, eventually resulted in premature termination of type VII collagen polypeptide. Furthermore the mother did not have the mutation c.8569G>T in exon 116. The other novel mutation (c.4879G>A) was detected within exon 51 of both patient and mother, thereby resulting in changing valine (Val) to isoleucine (Ile) in type VII collagen polypeptide. Taken together, in this study we identified compound heterozygosity for COL7A1 mutations (c.8569G>T and c.4879G>A) in moderately severe RDEB in a Korean patient. We hope that this data contribute to the expanding database on COL7A1 mutations in DEB.
Adolescent ; Amino Acid Substitution ; Asian Continental Ancestry Group/*genetics ; Collagen Type VII/*genetics ; DNA Mutational Analysis ; Epidermolysis Bullosa Dystrophica/*genetics/pathology ; Heterozygote ; Humans ; Korea ; Male ; Pedigree ; Phenotype ; Point Mutation ; Polymerase Chain Reaction