The G allele of -368T > G in SLC22A5, in which strong linkage disequilibrium was observed and the limited diversity of three haplotypes was estimated, was significantly associated with steroid resistance in Japanese patients with Crohn's disease (P = 0.016).
Two variants, 1672C>T in SLC22A4 and -207G>C in SLC22A5, were shown to alter these genes' functions and were identified as genetic susceptibility factors for Crohn's disease (CD).
Phenotype-genotype associations were evaluated in a Canadian cohort including 507 patients with CD, 216 patients with UC, and 352 ethnically matched controls genotyped for SLC22A4 C1672T, SLC22A5 G-207C, and the major CD-associated CARD15 variants.