Allelic variants of the adenosine triphosphate-binding cassette, subfamily B member 1 (ABCB1), is also known as the multidrug resistance gene (MDR1).
This gene encodes the membrane-bound efflux transporter P-glycoprotein 170.
The variants have been associated with inflammatory bowel disease (IBD) but with conflicting results.
Dr Clive Onnie and colleagues examined the association of ABCB1 C3435T and G2677T/A in patients with IBD.
| The TT genotype was significantly associated with severe ulcerative colitis|
|Inflammatory Bowel Diseases|
The researchers evaluated a large British case-control cohort of 828 Crohn's disease, 580 ulcerative colitis cases, and 285 healthy controls.
The effect of these variants was further examined with respect to phenotypic and epidemiological characteristics.
The team carried out a meta-analysis of their results, and those from 8 previously published association studies of the C3435T variant in IBD.
The researchers found that the 2677T allele was significantly increased in British ulcerative colitis cases compared with controls.
In particular, the TT genotype was significantly associated with severe ulcerative colitis, and the use of steroids in ulcerative colitis.
The researchers observed no significant association with C3435T and ulcerative colitis, 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 ulcerative colitis but not with Crohn's.
Dr Onnie's team concluded, “These results indicate that ABCB1 sequence variants are associated with a small increase in the risk of developing ulcerative colitis, and may influence disease behavior.”