Cyclooxygenase-2, multidrug resistance 1, and breast cancer resistance protein gene polymorphisms and inflammatory bowel disease in the Danish population

Objective. Crohn's disease (CD) and ulcerative colitis (UC) are characterized by an impaired mucosal defence to normal constituents of the intestinal flora and a dysregulated inflammatory response. The purpose of the study was to investigate whether single nucleotide polymorphisms (SNPs) in genes involved in these processes were associated with CD and UC. Material and methods. Allele frequencies of the cyclooxygenase 2 (COX-2/PTGS2/PGHS2) G-765C and breast cancer resistance protein (BCRP/ABCG2) C421A as well as allele and haplotype frequencies of multidrug resistance 1 (MDR1, ABCB1) SNPs G2677T/A, C3435T and G-rs3789243-A (intron 3) were assessed in a Danish case-control study comprising 373 CD and 541 UC patients and 796 healthy controls. Results. Carriers of the homozygous COX-2 and MDR1 intron 3 variant had a relatively high risk of CD, odds ratio (95% CI) (OR (95% CI))=2.86 ((1.34–5.88) p=0.006) and 1.39 ((0.99–1.92) p=0.054), respectively, and for UC of 2.63 ((1.33–5.26) p=0.005) and 1.28 ((0.96–1.51...