Purpose: Search for and identification of possible associations of recurrence-free urolithiasis with polymorphisms of urolithiasis candidate genes in the Russian population.
Materials and methods: The study involved 43 patients with recurrence-free urolithiasis, 13 (30.2%) women and 30 (69.8%) of men (main group) from Central Russia, and 189 healthy adults (control group) from the same region. The mean age of the main group was 42.5+/-13 years. The venous blood samples were used for the evaluation. Real-time PCR using the "Applied Biosystems" test systems was performed to determine the spectrum and frequency of eight urolithiasis candidate genes polymorphisms: tumor necrosis factor receptor gene (TNFRSF11B (rs3134057), vitamin D receptor gene (VDR, (rs1540339), extracellular calcium-sensing receptor gene (CASR, (rs2202127), calcium release-activatedcalcium modulator 1 gene (ORAI1, rs7135617), Klotho gene (KL, rs526906), nuclear estrogen receptor alpha-subunit gene (ESR1, rs851982), tumor necrosis factor 11 gene (TNFSF11, rs9525641), and 26 gene family anionic membrane transporter gene (SLC26A6, rs2310996). Fishers angular transformation and 2 test were used for statistical analysis of the data.
Results: For ORAI1 gene, differences in genotype and allele frequencies in the control and main groups are significant: p=0.0001 and p=0.013, respectively. For polymorphisms of the other seven genes studied, the differences in genotype and allele frequencies are non-significant. The results indicate the presence of the association between recurrence-free urolithiasis and calcium release-activatedcalcium modulator 1 gene polymorphism (ORAI1, rs7135617), both in genotypes and alleles.
Conclusions: In Russian population, genetic factors, in particular, ORAI1 (rs7135617) gene polymorphism, can play the role in the development of recurrence-free urolithiasis.
Keywords: gene polymorphism; genetic risk factors; recurrence-free urolithiasis; urolithiasis.