Promoter Polymorphisms of Natural Resistance-associated Macrophage Protein 1 Gene in Korean Patients with Inflammatory Bowel Diseases

Lee, Byoung Wook; Cho, Jai Ho; Lee, Gil Yeon; Kim, Hyo Jong; Chi, Sung Gil; Jeong, Yong Hee; Han, Yo Seb; Dong, Seok Ho; Kim, Byung Ho; Chang, Young Woon; Lee, Joung Il; Chang, Rin

Abstract

BACKGROUND/AIMS: Natural resistance-associated macrophage protein 1 (NRAMP1) gene controls the immune response to intracellular microbial pathogens in human. To identify the association between the NRAMP1 gene and susceptibility of inflammatory bowel disease (IBD) in Korean population, we examined three predominant alleles (allele 2, 3, and 7) that have been known to influence the transcriptional activity of the NRAMP1 gene. METHODS: Genomic DNA was extracted from blood lymphocytes by standard method in 70 patients with Crohn's disease (CD), 72 patients with ulcerative colitis (UC), and 52 healthy controls. To detect sequence polymorphisms in the NRAMP1 gene promoter, we performed nonisotopic genomic PCR-SSCP analysis. PCR products with different SSCP patterns were subjected to DNA sequencing analysis to verify sequence polymorphisms. RESULTS: The allele and carrier frequencies of allele 2 and 3 were similar in both patient and healthy control group. Although the statistical significance did not exist, the allele and carrier frequencies of allele 7 had higher tendency in patients with CD (10.7%, 21.4%) and UC (11.1%, 22.2%) than in the healthy control group (4.8%, 9.6%). CONCLUSIONS: Our findings suggest that the specific promoter polymorphism of the NRAMP1 gene may influence susceptibility to IBD in the Korean population. Further studies with a group of subjects are required to clarify our observations.