DNA: Irritable Bowel Syndrome’s SNPs

“Irritable bowel syndrome (IBS) affects approximately 10.5% of the population (6.6% of men and 14.0% of women).[1]”

This is a continuation of what seem to have become a series of DNA Snps associated with CFS and conditions typically co-morbid.

  • GI symptom severity was associated with ADRA1D rs1556832 (P = 0.010). [2015] –
    • rs1042717,  rs174697
    • not in 23AndMe

However this articles does include a table that may be helpful for understand what association means:


If the percentage in the Healthy Controls and the IBS Patients for one particular item are far enough apart, and after doing some mathematics, the researchers will conclude that is a positive or negative association of the SNP with a patient or a symptom. For example rs174697 for G/G we have 65.6% versus 78.8% (thus having it suggests IBS is more likely), while for A/G we have 28.1% versus 18.7% suggesting IBS is less likely (1.5x less likely – sometimes called the Odds Ratio or “OR” i.e. 28.1/18.7).

A meta-analysis of immunogenetic Case-Control Association Studies in irritable bowel syndrome [2015].

  • [PMID 21636646OA-icon.png] Association of TNFSF15 polymorphism with irritable bowel syndrome “The Crohn’s disease risk allele rs4263839 G in the TNFSF15 gene was significantly associated with an increased risk of both IBS (p=2.2×10(-5); OR 1.37) and more pronouncedly, IBS-C (p=8.7×10(-7); OR 1.79) in the entire sample.”
  • [PMID 21304977OA-icon.png] An investigation of genome-wide studies reported susceptibility loci for ulcerative colitis shows limited replication in north Indians.
  • [PMID 25028192] Associations between TNFSF15 polymorphisms and susceptibility to ulcerative colitis and Crohn’s disease: A meta-analysis
  • [PMID 25824902] A meta-analysis of immunogenetic Case-Control Association Studies in irritable bowel syndrome

Link: https://www.23andme.com/you/explorer/snp/?snp_name=rs4263839 

  • The bad pair is “GG” (I have “AG”)

Genetic variants in CDC42 and NXPH1 as susceptibility factors for constipation and diarrhoea predominant irritable bowel syndrome [2014].

“Two SNPs associated independently in the exploratory and validation cohort: rs17837965-CDC42 with IBS-C (ORexploratory=1.59 (1.05 to 1.76); ORvalidation=1.76 (1.03 to 3.01)) and rs2349775-NXPH1 with IBS-D (ORexploratory=1.28 (1.06 to 1.56); ORvalidation=1.42 (1.08 to 1.88)).”

Only one SNP is available in 23AndMe, the one associated with diarrhoea.

Link: https://www.23andme.com/you/explorer/snp/?snp_name=rs2349775 (was previously associated with neuroticism )

  • From the literature that I could find,  “CC” is likely the bad one.