Novel and recurrent mutations in the integrin beta 4 subunit gene causing lethal junctional epidermolysis bullosa with pyloric atresia

S. Iacovacci, S. Cicuzza, T. Odorisio, E. Silvestri, H. Kayserili, G. Zambruno, P. Puddu, Marina D'Alessio

Research output: Contribution to journalArticle

Abstract

In this study we examined two unrelated patients affected with the lethal variant of junctional epidermolysis bullosa with pyloric atresia (PA-JEB) who were found to carry mutations in the integrin β4 subunit gene (ITGB4). Although in both patients Northern blot analysis showed only a 50% reduction in the level of ITGB4 transcript, a complete lack (patient 1) or a strong reduction (patient 2) of β4 immunoreactivity was observed in the skin. Using immunoprecipitation analysis, integrin β4 could not be visualized in patient 1 cells while a markedly reduced amount (∼20%) of normal sized β4 chains was detected in patient 2. These data suggested the presence of ITGB4 mutations that interfere with both mRNA and protein stability. Using molecular analysis, patient 1 was shown to be a compound heterozygous for a single amino acid deletion (δN318) and a not yet identified mutation that induces a very rapid decay of the encoded mRNA transcript. Patient 2 was, instead, a compound heterozygous for a novel 4-bp tandem duplication (4298-4299ins4) and a previously described missense mutation (R252C). Our data support the notion that PA-JEB lethal phenotypes associated with a markedly decreased/absent αβ4 expression can be due not only to the presence of null alleles, but also to specific mutations leading to protein instability and/or altered function.

Original languageEnglish
Pages (from-to)716-720
Number of pages5
JournalExperimental Dermatology
Volume12
Issue number5
DOIs
Publication statusPublished - Oct 2003

Keywords

  • Hemidesmosomes
  • Inherited epidermolysis bullosa
  • Integrin β4

ASJC Scopus subject areas

  • Dermatology

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