Vitamin D receptor gene polymorphism and ulcerative colitis susceptibility in Han Chinese.

ABSTRACT

OBJECTIVE: Specific polymorphisms in the vitamin D receptor (VDR) gene have been associated with genetic susceptibility to inflammatory bowel disease (IBD) in different ethnic populations. METHODS: A total of 218 ulcerative colitis (UC) patients and 251 healthy controls were genotyped for VDR gene polymorphisms using PCR-restriction fragment length polymorphism (PCR-RFLP) assay. VDR gene polymorphisms (Apa I, Taq I, Bsm I and Fok I) were analyzed for both genotypic and phenotypic susceptibilities. RESULTS: Among the four examined VDR gene polymorphisms, the Bsm I polymorphism showed a slightly higher distribution in our study population than that in the previous studies. We also found that the increased frequency of the Bb genotype of the Bsm I VDR gene polymorphism was associated with UC in Han Chinese, as compared with healthy controls (28.4% vs. 18.7%, χ(2) = 6.044, P = 0.014, OR = 1.739, 95% CI = 1.122-2.697). Moreover, Bsm I polymorphic allele (B) frequency was significantly increased in the UC cases, as compared to the healthy controls (14.7% vs. 7.8% χ(2) = 6.222, P = 0.013; OR = 1.670, 95% CI = 1.113-2.506). In contrast, the other three VDR gene polymorphisms (Apa I, Taq I and Fok I) were not associated with UC susceptibility in the Han Chinese cohort. In addition, none of these four VDR polymorphisms had statistical association with clinicopathological parameters of these UC patients. CONCLUSION: This study demonstrated a probable association of the Bsm I polymorphism of the VDR gene with ulcerative colitis susceptibility in Han Chinese.