SEARCH

SEARCH BY CITATION

Keywords:

  • COL7A1;
  • dystrophic epidermolysis bullosa;
  • genotype–phenotype;
  • recurrent mutation;
  • type VII collagen

Summary

Background  Mutations in the type VII collagen gene (COL7A1) are responsible for dominant and recessive forms of dystrophic epidermolysis bullosa (DEB). These mutations are usually specific for individual families; only a few cases of recurring mutations have been identified.

Objectives  Forty-three unrelated Hungarian and German patients with different DEB phenotypes were screened for novel and recurrent COL7A1 mutations.

Methods  All patients were classified based on clinical and genetic findings, skin immunofluorescent antigen mapping, and electron microscopic studies. Mutation analysis was performed by amplification of genomic DNA with polymerase chain reaction using COL7A1-specific primers, heteroduplex analysis, and direct nucleotide sequencing. Restriction endonuclease digestion was used for family screening and mutation verification.

Results  In this group of patients, the splice-site mutation 425A[RIGHTWARDS ARROW]G was observed frequently, in 11 of 86 alleles (12·8%), once in homozygous form and in nine cases in heterozygous form. One of 100 control alleles from clinically unaffected individuals also carried the mutation. We also identified three novel mutations: the 976-3C[RIGHTWARDS ARROW]A splice-site mutation, and the 4929delT and 8441-15del20 deletions.

Conclusions  High recurrence of the splice-site mutation 425A[RIGHTWARDS ARROW]G in central European patients with DEB should be taken into account when designing COL7A1 mutation detection strategies. Reporting of three novel COL7A1 mutations in this study further emphasizes the molecular heterogeneity of DEB and provides more information for studies on genotype–phenotype correlations in different DEB subtypes.