The association between a single nucleotide polymorphism of interleukin-4 gene (IL4) at position-590 of the promoter region (IL4-590 SNP) and inflammatory bowel disease (IBD) was determined in 34 Crohn's disease (CD) and 66 ulcerative colitis (UC) Iraqi patients, as well as 43 controls. The results revealed thatcomparing IL4-590 genotypes and alleles between IBD patients and controls revealed some significant variations. Among CD patients, it was observed that frequencies of TT genotype (52.9 vs. 11.6%; P = 1.2*10-4 ) and T allele (70.6 vs. 24.4%; P = 1.6*10-8 ) were significantly increased in patients compared to controls, and the associated RR values were 8.55 and 7.43, respectively. In contrast, CC genotype (11.8 vs. 62.8%, P = 5.6*10-6 ) and C allele (29.4 vs. 75.6%; P = 1.6*10-8 ) frequencies were significantly decreased in CD patients, and the associated PF values were 0.58 and 0.65, respectively. In the case of UC, frequencies of TC genotype (69.7 vs. 25.6%; RR = 6.69; P = 1.1*10-5 ) and T allele (62.1 vs. 24.4%; RR = 5.08; P = 4.6*10-8 ) were significantly increased in patients compared to controls, while CC genotype (3.0 vs. 62.8%; PF = 0.62; P = 2.5*10-12) and C allele (37.9 vs. 75.6%; PF = 0.61; P = 1.6*10-8 ) frequencies were significantly decreased. However, no such variation was observed between CD and UC patients. These findings suggest that IL4-590 SNP might have a role in the etiopathogenicmechanism of CD and UC.
