Additionally, IRF1 was correlated with high-sensitivity C-reactive protein, erythrocyte sedimentation rate, Crohn's disease activity index, Crohn's disease endoscopic index of severity, and simple endoscopic score for Crohn's disease in Crohn's disease and with high-sensitivity C-reactive protein, erythrocyte sedimentation rate, Mayo score, Baron score, modified Baron score, Rachmilewitz score, ulcerative colitis endoscopic index of severity, ulcerative colitis colonoscopic index of severity, and disease duration in ulcerative colitis.
Two of the loci are related to common chronic inflammatory diseases: the first, at locus 5q31.1 (SLC22A5, SLC22A4, IRF1), lies immediately adjacent to a locus linked to Crohn disease (P value for lead SNP, 1.24 x 10(-12)) and the second, at locus 17q25.1 (CD300LF, SLC9A3R1, NAT9), has been associated with psoriasis (P value for lead SNP, 7.72 x 10(-11)).
We confirm the importance of IBD5 to CD susceptibility, demonstrate that the locus may play a role in NJ individuals only, and establish that IRF1, PDLIM, and P4HA2 may be equally as likely to contain the IBD5 causal variant as the OCTN genes.
Two other SNPs, rs11242115 in IRF1 and rs17166050 in RAD50, lying outside the 250 kb risk haplotype, also showed CD association (P=0.019 and P=0.0080, respectively).