Tumor Necrosis Factor-α Gene Polymorphisms in Korean Children with Inflammatory Bowel Disease

Purpose: The aim of this study was to investigate the existence of TNF-α polymorphisms in Korean children with Crohn’s disease (CD), ulcerative colitis (UC), as compared to healthy controls. Methods: Blood samples were obtained from 40 patients with CD, 14 patients with UC, and 30 healthy controls. Genotyping for 5 TNF-α polymorphisms (G238A, G308A, C857T, C863A, and T1031C) was performed. The allele frequencies for the inflammatory bowel diseases, CD and UC, were measured in patients with these disease and in healthy controls, and these allele frequencies were compared between the 3 groups. We examined the significant association between polymorphism and disease phenotype, such as location, behavior, perianal disease, and pediatric Crohn’s activity index (PCDAI) in CD. Results: Based on our findings, the TNF-α allele frequencies of G238A, G308A, C857T, C863A, and T1031C were 3.3, 8.3, 16.7, 16.7, 21.7% in healthy control, 2.5%, 7.5%, 18.8%, 20.0%, 22.5% in CD, 7.1%, 7.1%, 7.1%, 21.4%, 28.6% in UC. They were no statistically significant differences between the 3 groups. There were no associations between genotypes and phenotypes in CD, except a statistically significant higher allele frequency of G238A in ileal type (L1) disease (p=0.010). Conclusion: Our results indicate that 5 TNF-α polymorphisms do not seem to be associated with susceptibility to inflammatory bowel disease in Korean pediatric patients even though young patients were anticipated to have a stronger genetic affiliation for these diseases than adult patients. We think that further studies are needed to find those genes associated with susceptibility to CD and UC in Korean pediatric patients with inflammatory bowel disease. (Korean J Pediatr Gastroenterol Nutr 2011; 14: 269∼278)