ABSTRACT
Inflammatory bowel disease [IBD] is a chronic, relapsing, inflammatory disorder of the gastrointestinal tract that includes two entities, Crohn's disease [CD] and ulcerative colitis [UC]. As with other complex diseases, both genetic susceptibility and environmental factors play role in the pathogenesis of these diseases. The tumor necrosis factor alpha [TNF-alpha] gene is located in the IBD3 region on chromosome 6p21 which is a good functional candidate for involvement in susceptibility to IBD. In addition, the promoter region of TNF-alpha contains various polymorphisms that have shown a significant association with IBD. In this case control study we investigated the TNF-alpha -857 polymorphism in 109 patients [89 UC and 16 CD] who suffered from IBD and 100 healthy age, sex and ethnicity matched adults selected from the same population, as the control group. The polymorphism was checked by amplification refractory system [ARMS] and polymerase chain reaction [PCR]. Investigation of the association of TNF-alpha -857 gene promoter polymorphism with both types of IBD showed no significant difference in genotype and allele frequencies of this polymorphism between UC patients and controls. However, a possible association of TNF-alpha -857 polymorphism [p=0.03] was identified with CD. TNF-alpha -857 polymorphism may have a role in the development of CD in the Iranian Azeri Turkish population.