Cloning of the human type XVII collagen gene (COL17A1), and detection of novel mutations in generalized atrophic benign epidermolysis bullosa

Biljana Gatalica, Leena Pulkkinen, Kehua Li, Kirsti Kuokkanen, Markku Ryynänen, John A. McGrath, Jouni Uitto

Research output: Contribution to journalArticlepeer-review

109 Citations (Scopus)

Abstract

Generalized atrophic benign epidermolysis bullosa (GABEB) is a nonlethal variant of junctional epidermolysis bullosa (JEB). Previous findings have suggested that type XVII collagen is the candidate gene for mutations in this disease. We now have cloned the entire human type XVII collagen gene (COL17A1) and have elucidated its intron-exon organization. The gene comprises 56 distinct exons, which span ~52 kb of the genome, on the long arm of chromosome 10. It encodes a polypeptide, the α1(XVII) chain, consisting of an intracellular globular domain, a transmembrane segment, and an extracellular domain that contains 15 separate collagenous subdomains, the largest consisting of 242 amino acids. We also have developed a strategy to identify mutations in COL17A1 by use of PCR amplification of genomic DNA, using primers placed on the flanking introns. The PCR products are scanned for sequence variants by heteroduplex analysis using conformation-sensitive gel electrophoresis and then are subjected to direct automated sequencing. We have identified several intragenic polymorphisms in COL17A1, as well as mutations, in both alleles, in two Finnish families with GABEB. The probands in both families showed negative immunofluorescence staining with an anti- type XVII collagen antibody. In one family, the proband was homozygous for a 5-bp deletion, 2944del5, which resulted in frameshift and a premature termination codon of translation. The proband in the other family was a compound heterozygote, with one allele containing the 2944del5 mutation and the other containing a nonsense mutation, Q1023X. These results expand the mutation database in different variants of JEB, and they attest to the functional importance of type XVII collagen as a transmembrane component of the hemidesmosomes at the dermal/epidermal junction.

Original languageEnglish
Pages (from-to)352-365
Number of pages14
JournalAmerican Journal of Human Genetics
Volume60
Issue number2
Publication statusPublished - 1997 Feb

All Science Journal Classification (ASJC) codes

  • Genetics
  • Genetics(clinical)

Fingerprint

Dive into the research topics of 'Cloning of the human type XVII collagen gene (COL17A1), and detection of novel mutations in generalized atrophic benign epidermolysis bullosa'. Together they form a unique fingerprint.

Cite this