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Cryptogenic multifocal ulcerating stenosing enteritis associated with homozygous deletion mutations in cytosolic phospholipase A2-α

Authors

  • M.A. Brooke
  • H.J. Longhurst
  • V. Plagnol
  • N.S. Kirkby
  • J.A. Mitchell
  • F. Rüschendorf
  • T.D. Warner
  • D.P. Kelsell
  • T.T. MacDonald

Journal

  • Gut

Citation

  • Gut 63 (1): 96-104

Abstract

  • OBJECTIVE: Cryptogenic multifocal ulcerating stenosing enteritis (CMUSE) is an extremely rare, but devastating, disease of unknown aetiology. We investigated the genetic basis of this autosomal recessive condition in a pair of affected siblings who have 40-year histories of catastrophic gastrointestinal and extraintestinal disease. DESIGN: Genome-wide single-nucleotide polymorphism homozygosity mapping in the two affected family members combined with whole-exome sequencing of one affected sibling. This was followed by confirmatory Sanger sequencing of the likely disease-causing sequence variant and functional studies in affected and unaffected family members. RESULTS: Insertion/deletion variation analysis revealed the presence of a homozygous 4 bp deletion (g.155574_77delGTAA) in the PLA2G4A gene, located in the splice donor site directly after exon 17 (the penultimate exon) of the gene in both affected siblings. This introduces a frameshift of 10 amino acids before a premature stop codon (p.V707fsX10), which is predicted to result in the loss of 43 amino acids (residues 707-749) at the C-terminus of cytosolic phospholipase A2-{alpha} (cPLA(2)alpha). cPLA(2){alpha} protein expression was undetectable in the gut of both siblings, with platelet aggregation and thromboxane A(2) production, as functional assays for cPLA(2){alpha} activity, grossly impaired. CONCLUSIONS: We have identified mutations in PLA2G4A as a cause of CMUSE in two affected siblings. Further studies are needed to determine if mutations in this gene are also responsible for disease of a similar phenotype in other cases.


DOI

doi:10.1136/gutjnl-2012-303581