title: A novel homozygous splice site mutation in COL7A1 in a Chinese patient with severe recessive dystrophic epidermolysis bullosa and squamous cell carcinoma.
abstract: BACKGROUND
  Recessive dystrophic epidermolysis bullosa (RDEB) is an inherited blistering skin disorder caused by mutations in COL7A1 gene encoding type VII collagen, the major component of anchoring fibrils in the dermo-epidermal junction. The development of cutaneous squamous cell carcinoma (SCC) is one of the most serious complications of this disease. We report herein a Chinese patient with the severe generalized subtype of RDEB (RDEB-sev gen) complicated by SCC.
  
  
  METHODS
  Skin biopsies were examined for histology, basement membrane ultrastructure, and type VII collagen expression. Genomic DNA was extracted from the peripheral blood samples and subjected to polymerase chain reaction amplification and direct automated DNA sequencing.
  
  
  RESULTS
  Histopathological examination of the patient's skin revealed an undetectable expression of type VII collagen polypeptides in the basement membrane zone. Mutation analysis identified a novel splice site mutation in intron 64 (IVS64+5g->a) of COL7A1 gene, which resulted in an in-frame deletion of exon 64 in both alleles.
  
  
  CONCLUSIONS
  This report contributes to the expanding database of COL7A1 mutations and emphasizes the need to elucidate the underlying genetic mechanisms associated with the increased incidence of SCC in RDEB patients.
authors.affiliation: Division of Plastic, Reconstructive and Aesthetic Surgery, Department of Surgery, Prince of Wales Hospital, Chinese University of Hong Kong, Hong Kong, China.
authors.forename: Lin
authors.initials: L
authors.lastname: Huang
authors.forename: Yim-Ping
authors.initials: YP
authors.lastname: Wong
authors.forename: Andrew
authors.initials: A
authors.lastname: Burd
mesh_terms: D044466:Asian People / Q000235:genetics; D001483:Base Sequence; D001485:Basement Membrane / Q000378:metabolism / Q000473:pathology / Q000648:ultrastructure; D024143:Collagen Type VII / Q000235:genetics* / Q000378:metabolism; D016108:Epidermolysis Bullosa Dystrophica / Q000235:genetics* / Q000378:metabolism / Q000473:pathology / Q000601:surgery; D005091:Exons; D005808:Genes, Recessive; D006720:Homozygote; D006801:Humans; D008297:Male; D008969:Molecular Sequence Data; D018307:Neoplasms, Squamous Cell / Q000235:genetics* / Q000378:metabolism / Q000473:pathology / Q000601:surgery; D012326:RNA Splicing; D017384:Sequence Deletion; D012867:Skin / Q000378:metabolism / Q000473:pathology / Q000648:ultrastructure; D012878:Skin Neoplasms / Q000235:genetics* / Q000378:metabolism / Q000473:pathology / Q000601:surgery; D055815:Young Adult
chemical_list: D024143:Collagen Type VII