Association of TRPV5 gene polymorphism with calcium urolithiasis: a case-control study from West Bengal, India

Purpose Present study was intended to investigate the potential contribution of TRPV5 gene polymorphisms with calcium urolithiasis in the population of West Bengal, India. Methods A case-control study was performed with 152 calcium urolithiasis patients and 144 corresponding healthy controls. Epidemiological and clinical parameters were documented as well as peripheral blood sample was collected from each individual, followed by genomic DNA isolation. Then to identify genetic variants of TRPV5, the entire coding region and exon-intron boundaries of the gene were amplified by polymerase chain reaction using specific oligonucleotide primers and then genotypes were determined by bi-directional DNA sequencing and sequence alignment between case and control individuals. Results Urinary calcium excretion was found to be significantly high (p value < 0.0001) in urolithiasis patients as compared to controls. A total of 14 SNPs were obtained of which one non-synonymous (rs4236480; p.Arg154His; CGT > CAT), one synonymous (rs4252417; p.Tyr278Tyr; TAC > TAT) and three intronic (rs4252400, rs4252402, rs4236481) SNPs were found to be significantly associated with increased risk of urolithiasis. For non-synonymous SNP rs4236480, 'A' was found to be the risk allele (OR 1.77, 95% CI 1.24-2.51; p value 0.001) and genotype frequency analysis revealed that individuals carrying variant genotype AA were more prone to the disease than individuals with wild genotype GG (OR 3.09, 95% CI 1.26-7.59; p value 0.0136), indicating AA as the risk genotype. Conclusions The non-synonymous SNP rs4236480 showed significant association with urolithiasis risk in West Bengal population of India. Future translational and larger population-based studies are required to validate our finding.