Association of polymorphism BsmI of vitamin D receptor gene (VDR) with inflammatory bowel diseases

Abstract

Among the numerous genetic factors of Crohn s disease (CD) and ulcerative colitis (UC), polymorphisms of the vitamin D receptor gene (VDR) associated with disorders of congenital and adaptive immunity, as well as the barrier function of the intestinal epithelium, are increasingly being addressed. Aim: to assess the prevalence, clinical, diagnostic and prognostic significance of BsmI polymorphism of the VDR gene in patients with CD and UC among the residents of the Kemerovo region of the Russian Federation. Material and methods. The study included 60 patients with CD, 76 patients with UC and 85 controls. Genotyping was performed by allele-specific PCR with electrophoretic detection of amplification products. Results. We have found that the frequency of the allele B polymorphism of the VDR BsmI gene was higher among patients with UC than in patients with CD and controls (44 %, 38 % and 26 %, respectively, p = 0.02), which is two times increased the risk of developing UC (OR = 2.2; 95 % CI: 1.2-4.1). In the case of carriers of the b/b genotype the risk of UC decreased (OR = 0.4; 95 % CI: 0.2-0.7). It has been shown that in carriers of allele B, the clinical implementation of CD and UC develops later than in patients with the b/b genotype (31.0 vs. 28.5 years and 43.0 vs. 28.5 years, respectively; p = 0.04). It was shown that the carriage of allele B by 5.5 times increased the risk of colitis in CD (p = 0.03). Conclusions. The B allele of the BsmI polymorphism of the VDR gene is a predictor of elevated risk of UC and colitis in CD with an increase in the age of diagnoses. Genotype b/b has a protective effect in the development of UC among the residents of the Kemerovo region of the Russian Federation.