Associations of allelic variants of the multidrug resistance gene (ABCB1 or MDR1) and inflammatory bowel disease and their effects on disease behavior: a case-control and meta-analysis study

Inflamm Bowel Dis. 2006 Apr;12(4):263-71. doi: 10.1097/


Background: Allelic variants of the ATP-binding cassette, subfamily B member 1 (ABCB1), also known as the multidrug resistance gene (MDR1) that encodes the membrane-bound efflux transporter P-glycoprotein 170 (PGP-170), have been associated with inflammatory bowel disease but with conflicting results.

Methods: The present study examined the association of ABCB1 C3435T and G2677T/A in a large British case-control cohort of 828 Crohn's disease, 580 ulcerative colitis (UC) cases, and 285 healthy controls. The effect of these variants was further examined with respect to phenotypic and epidemiological characteristics. A meta-analysis was carried out of our results and those from 8 previously published association studies of the C3435T variant in inflammatory bowel disease.

Results: The 2677T allele was significantly increased in British UC cases compared with controls (45.2% vs. 39.6%; P = 0.034). In particular, the TT genotype was significantly associated with severe UC (odds ratio [OR] 1.90; 95% CI 1.01-3.55) and the use of steroids in UC (OR 1.77; 95% CI 1.08-2.88). No significant association was seen with C3435T and UC, Crohn's disease, or any clinical subgroup. A meta-analysis of 9 association studies of C3435T showed a significant association of the 3435T allele with UC (OR 1.12; 95% CI 1.02-1.23; P = 0.013) but not with CD.

Conclusions: These results indicate that ABCB1 sequence variants are associated with a small increase in the risk of developing UC and may influence disease behavior.

Publication types

  • Comparative Study
  • Meta-Analysis
  • Research Support, Non-U.S. Gov't

MeSH terms

  • ATP Binding Cassette Transporter, Subfamily B
  • ATP Binding Cassette Transporter, Subfamily B, Member 1 / genetics*
  • Adolescent
  • Adult
  • Aged
  • Aged, 80 and over
  • Alleles
  • Child
  • Child, Preschool
  • DNA / genetics*
  • Disease Progression
  • Female
  • Follow-Up Studies
  • Gene Frequency*
  • Genotype
  • Humans
  • Inflammatory Bowel Diseases / genetics
  • Inflammatory Bowel Diseases / metabolism*
  • Male
  • Middle Aged
  • Organic Anion Transporters / genetics*
  • Polymorphism, Genetic*
  • Retrospective Studies


  • ABCB1 protein, human
  • ATP Binding Cassette Transporter, Subfamily B
  • ATP Binding Cassette Transporter, Subfamily B, Member 1
  • Organic Anion Transporters
  • DNA