Crohn＇s disease in Japanese is associated with a SNP-haplotype of N-acetyltransferase 2 gene

AIM： To investigate the frequency and distribution of /V-acetyltransferase 2 （NAT2） and uridine 5＇-diphosphate （UDP）-glucuronosyltransferase 1A7 （UGT1A7） genes in patients with ulcerative colitis （UC） and Crohn＇s disease （CD）. METHODS： Frequencies and distributions of IVAT2 and UGT1A7SNPs as well as their haplotypes were investigated in 95 patients with UC, 60 patients with CD, and 200 gender-matched, unrelated, healthy, control volunteers by PCR-restriction fragment length polymorphism （RFLP）, PCR-denaturing high-performance liquid chromatography （DHPLC）, and direct DNA sequencing. RESULTS： Multiple logistic regression analysis revealed that the frequency of haplotype, NAT2＊7B, significantly increased in CD patients, compared to that in controls （P= 0.0130, OR = 2.802, 95%CI = 1.243-6.316）. However, there was no association between NAT2 haplotypes and UC, or between any UGT1A7haplotypes and inflammatory bowel disease （IBD）. CONCLUSION： It is likely that the NAT2 gene is one ofthe determinants for CD in Japanese. Alternatively, a new CD determinant may exist in the 8p22 region, where NAT2 is located.