Genetic epidemiology and pharmacogenetics in irritable bowel syndrome

Michael Camilleri, David A. Katzka

Research output: Contribution to journalReview articlepeer-review

84 Scopus citations


The objectives of this review are twofold. Our first objective is to evaluate the evidence supporting a role for genetics in irritable bowel syndrome (IBS). Specific examples of the associations of genetic variation and symptoms, syndromes, and intermediate phenotypes, including neurotransmitter (serotonergic, α 2-adrenergic, and cannabinoid) mechanisms, inflammatory pathways (IL-10, TNFα, GNβ3, and susceptibility loci involved in Crohn's disease), and bile acid metabolism, are explored. The second objective is to review pharmacogenetics in IBS, with the focus on cytochrome P-450 metabolism of drugs used in IBS, modulation of motor and sensory responses to serotonergic agents based on the 5-hydroxytryptamine (5-HT) transporter- linked polymorphic region (5-HTTLPR) and 5-HT 3 genetic variants, responses to a nonselective cannabinoid agonist (dronabinol) based on cannabinoid receptor (CNR1) and fatty acid amide hydrolase (FAAH) variation, and responses to a bile acid (sodium chenodeoxycholate) and bile acid binding (colesevelam) based on klothoβ (KLB) and fibroblast growth factor receptor 4 (FGFR4) variation. Overall, there is limited evidence of a genetic association with IBS; the most frequently studied association is with 5-HTTLPR, and the most replicated association is with TNF superfamily member 15. Most of the pharmacogenetic associations are reported with intermediate phenotypes in relatively small trials, and confirmation in large clinical trials using validated clinical end points is still required. No published genome-wide association studies in functional gastrointestinal or motility disorders have been published.

Original languageEnglish (US)
Pages (from-to)G1075-G1084
JournalAmerican Journal of Physiology - Gastrointestinal and Liver Physiology
Issue number10
StatePublished - May 15 2012


  • 5-hydroxytryptamine transporter-linked polymorphic region
  • Adrenergic
  • Bile acid malabsorption
  • Inflammation
  • Klothoß
  • Serotonergic
  • Solute carrier 6A4
  • Susceptibility

ASJC Scopus subject areas

  • Physiology
  • Hepatology
  • Gastroenterology
  • Physiology (medical)


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