Association study between two polymorphisms of tumor necrosis factor ligand superfamily member 15 (TNFSF15) gene and ulcerative colitis in south-west of Iran

Background and aims Ulcerative colitis (UC) is the most prevalent clinical manifestation of the inflammatory bowel disease (IBD). Several candidate genes have been suggested to be involved in the genetic susceptibility or resistance in the development of UC. Among them, tumor necrosis factor ligand superfamily member 15 (TNFSF15) have been reported in association with IBD in several studies. The aim of this study was to investigate the association of TNFSF15 gene polymorphisms located in the promoter region, including rs6478108 (G/A -9706) and rs3810936 (G/A -15524) in Iranian patients with UC. Methods In this way, the two single nucleotide polymorphisms were studied in 115 patients with UC and 115 healthy controls with the same ethnic group from south-west of Iran. The genomic DNA of samples was genotyped using TaqMan Real-time PCR assay. This case-control study was conducted at the Department of Immunology, Jundishapur University of Medical Sciences, Ahvaz, Iran. Results and conclusion Our results did not confirm the formerly reported association of the studied polymorphisms with UC disease in comparison with healthy controls, neither with the type of the clinical forms of Colitis in the studied Iranian population. Comparing the genotype frequency of single nucleotide polymorphism (SNP) rs6478108, wild-type homozygous and heterozygote and mutant homozygote were 33%, 55.7%, and 11.3% in cases vs. 34.8%, 50.4%, and 14.8% in the controls (P = 0.6). The genotype frequency of SNP rs3810936 were 20.9%, 40.9%, and 38.2% in the cases compared to 18.3%, 44.3%, and 37.4% in controls, which was not significant (P = 0.8). As multiple ethnic groups reside in all around the country, further studies using different ethnicities and/or larger sample size are required to clarify the role of these polymorphisms in the genetic susceptibility of UC in Iranian populations.