No association between TNFSF15 and IL23R with ulcerative colitis in Koreans

Recent genome-wide association studies have shown that some Crohn's disease (CD)-associated loci also contribute to ulcerative colitis (UC) susceptibility. To understand the genetic relationship between the two forms of inflammatory bowel disease, we investigated the well-established CD-susceptibility genes TNFSF15 (tumor necrosis factor ligand superfamily, member 15) and IL23R in Korean patients with UC. Eight TNFSF15 and five IL23R single-nucleotide polymorphisms were genotyped in 654 patients with UC and in 601 healthy controls. There was no association between TNFSF15 or IL23R variants and UC in Korean individuals, in contrast to previous reports of a shared association of the IL23R gene with both CD and UC in Caucasian individuals. Our data suggest that neither TNFSF15 nor IL23R variants contribute to UC susceptibility in Koreans.