Relationship Between Gene Promoter Polymorphism Of Cyp27b1 And Susceptibility To Ulcerative Colitis

Ulcerative colitis (UC) is a group of chronic intestinal inflammatory disease, whose etiology is still unknown. Most of the views presumed that it is a kind of non-specific inflammatory diseases, which can be induced under the role of environmental factors and autoimmune disorders of the host who carry the genetic susceptibility gene. Epidemiological evidence showed a potential hereditary susceptibility contribution to UC, including high incidence of UC in certain ethnic groups, family-cluster phenomenon and the concordance in identical twins. This was validated by the results of holo-genome scanning and predisposing genes. Therefore, the genetic susceptibility plays a very important role in the etiopathogenisis of UC.Extensive research showed that Vitamin D (Vit D) and UC is closely associated. The reduction of Vit D production, and/or the insufficiency of its role, will significantly increase the risk of alimentary infection, participate into the impairment of mucous membrane, and increase the risk of UC. cyp27b1 is an encoding gene of Vit D rate-limiting enzyme which determines the biological activity of Vit D. There is a polymorphism at the promoter region. The heterogenesis may influence the function of Vit D, and then indirectly induce to UC.Objective: To investigate the relationship between cyp27b1 gene promoter polymorphism and UC in Chinese patients with Han nationality. The purpose of the research was to establish the foundation for further studying the pathogenesis of UC and to offer an instructor for UC therapy.Methods: A case-control was designed in this study. A total of 67 Han patients in Hebei with UC and 70 healthy controls matched for age, sex and nation were surveyed. Gene polymorphism was determined by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). The representation of genotype in the patients and controls was detected accorrding to Hardy-Weinberg equilibrium. Pearsonχ2 was used by SPSS13.0 software to analysis the association between cyp27b1 polymorphisms and the genetic geneticsusceptibility of UC.Results: The genotypic distribution of CYP27B1 gene-1260 site showed no deviation from Hardy-Weinberg equilibrium. The genotype and allele frequencies of cyp27b1-1260A/C were CC 56.7%, AA 6.0%, AC 37.3%, C 75.4% and A 25.6% in the UC group, 34.3%, 25.7%, 40.0%, 54.3% and 45.7% in the control group, respectively. Significant differences was found in the genotype and allele frequencies in -1260A/C polymorphism between the UC and the control group (χ2=12.180, P<0.05;χ2=13.313, P<0.05), CC genotype and C allele appeared significantly more frequent in the UC compared to the controls (χ2=6.952, P<0.05;χ2=13.313, P<0.05), yielding an OR of 2.511 (95% CI: 1.259-5.001) and 0.388 (95% CI: 0.232-0.649).Conclusion: cyp27b1 promoter-1260 polymorphism is associated with UC, cyp27b1-1260C is the predisposing genes.