Compound heterozygosity for missense (L156P) and nonsense (R554X) mutations in the beta4 integrin gene (ITGB4) underlies mild, nonlethal phenotype of epidermolysis bullosa with pyloric atresia

Am J Pathol. 1998 Apr;152(4):935-41.

Abstract

Mutations in the genes encoding the subunit polypeptides of the alpha6beta4 integrin (ITGA6 and ITGB4, respectively) have been previously demonstrated in patients with a lethal form of epidermolysis bullosa with congenital pyloric atresia (OMIM #226730). In this study, we demonstrate for the first time ITGB4 mutations in nonlethal phenotype of epidermolysis bullosa with congenital pyloric atresia. Specifically, the proband was shown to be a compound heterozygote for a missense mutation (L156P) and a nonsense mutation (R554X). The leucine substitution by proline was shown to affect a residue, which was precisely conserved in different human, rodent, and drosophila integrin-beta polypeptides, and consequently disrupts the alpha-helix formation of the polypeptide segment as determined by Garnier alpha-helicity plot. The nonsense mutation in another allele was accompanied by undetectable levels of the corresponding mRNA transcript, as determined by reverse transcription-polymerase chain reaction. The presence of a missense mutation, when combined with a premature termination codon mutation, may explain the milder blistering tendency of the skin in this patient.

Publication types

  • Case Reports
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Amino Acid Sequence
  • Antigens, CD / genetics*
  • Blotting, Western
  • Epidermolysis Bullosa / complications
  • Epidermolysis Bullosa / genetics*
  • Epidermolysis Bullosa / pathology
  • Fluorescent Antibody Technique, Indirect
  • Heterozygote
  • Humans
  • Immunohistochemistry
  • Infant
  • Integrin beta4
  • Integrins / genetics
  • Intestinal Atresia / complications
  • Intestinal Atresia / genetics*
  • Intestinal Atresia / pathology
  • Male
  • Molecular Sequence Data
  • Mutation
  • Pedigree
  • Polymerase Chain Reaction
  • Pylorus / abnormalities*
  • Transcription, Genetic

Substances

  • Antigens, CD
  • Integrin beta4
  • Integrins