Exome Analysis of Rare and Common Variants within the NOD Signaling Pathway

Sci Rep. 2017 Apr 19:7:46454. doi: 10.1038/srep46454.

Abstract

Pediatric inflammatory bowel disease (pIBD) is a chronic heterogeneous disorder. This study looks at the burden of common and rare coding mutations within 41 genes comprising the NOD signaling pathway in pIBD patients. 136 pIBD and 106 control samples underwent whole-exome sequencing. We compared the burden of common, rare and private mutation between these two groups using the SKAT-O test. An independent replication cohort of 33 cases and 111 controls was used to validate significant findings. We observed variation in 40 of 41 genes comprising the NOD signaling pathway. Four genes were significantly associated with disease in the discovery cohort (BIRC2 p = 0.004, NFKB1 p = 0.005, NOD2 p = 0.029 and SUGT1 p = 0.047). Statistical significance was replicated for BIRC2 (p = 0.041) and NOD2 (p = 0.045) in an independent validation cohort. A gene based test on the combined discovery and replication cohort confirmed association for BIRC2 (p = 0.030). We successfully applied burden of mutation testing that jointly assesses common and rare variants, identifying two previously implicated genes (NFKB1 and NOD2) and confirmed a possible role in disease risk in a previously unreported gene (BIRC2). The identification of this novel gene provides a wider role for the inhibitor of apoptosis gene family in IBD pathogenesis.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Case-Control Studies
  • Child
  • Child, Preschool
  • Cohort Studies
  • Exome / genetics
  • Exome Sequencing
  • Female
  • Genetic Predisposition to Disease
  • Genetic Variation
  • Genome-Wide Association Study
  • Humans
  • Infant
  • Inflammatory Bowel Diseases / genetics*
  • Inflammatory Bowel Diseases / metabolism
  • Inhibitor of Apoptosis Proteins / genetics
  • Inhibitor of Apoptosis Proteins / metabolism
  • Male
  • Models, Biological
  • Mutation
  • Nod Signaling Adaptor Proteins / genetics*
  • Nod Signaling Adaptor Proteins / metabolism
  • Nod2 Signaling Adaptor Protein / genetics
  • Nod2 Signaling Adaptor Protein / metabolism
  • Signal Transduction / genetics
  • Ubiquitin-Protein Ligases / genetics
  • Ubiquitin-Protein Ligases / metabolism

Substances

  • Inhibitor of Apoptosis Proteins
  • NOD2 protein, human
  • Nod Signaling Adaptor Proteins
  • Nod2 Signaling Adaptor Protein
  • BIRC2 protein, human
  • Ubiquitin-Protein Ligases