Relationship of vitamin D receptor gene polymorphisms in Helicobacter pylori gastric patients

PURPOSE: The present study aimed to investigate the association between the human VDR gene and Helicobacter pylori infection. PATIENTS AND METHODS: A cross-sectional study was conducted on 208 adult patients with upper gastrointestinal symptoms. Gastric biopsy specimens were obtained from each patient for molecular DNA and histological examination. Patients were genotyped for VDR gene polymorphisms using polymerase chain reaction and restriction fragment length polymorphism analysis. RESULTS: The allelic and genotypic distribution analyses of the FokI, ApaI and TaqI polymorphisms of the VDR gene did not show distribution differences between H. pylori-positive and -negative groups. The genotype distribution observed for polymorphism BsmI deviated significantly from what was expected in a Hardy–Weinberg equilibrium test in the H. pylori-positive group (χ(2)=29.048, p<0.001). The distribution of BsmI genotypes differed significantly between the H. pylori-negative and H. pylori-positive groups (p=0.0034), where the frequency of the bb genotype increased among H. pylori-positive individuals compared with those without infection (63.25% versus 50.55%, respectively). Conversely, the H. pylori-negative group showed a Bb frequency that was 20.27% higher than in the infected group. CONCLUSION: We identified a possible association between the BsmI polymorphism and infection by H. pylori. However, further research is required to clarify this relationship.