Investigation of the association of G-7A and T-138C single nucleotide polymorphisms on the promoter of MGP gene with renal stone

Introduction: Renal stones, due to their heavy costs of diagnosis and treatment, have a considerable financial burden on health system. Family history and genetic susceptibility are important factors in stone formation. Matrix Gla-protein (MGP) is a gene that has a known role in inhibition of arterial calcification. It is thought that MGP may be involved in pathogenesis of calcium nephrolithiasis as an ectopic calcification. Objectives: This study aims to demonstrate association of G-7A and T-138C single nucleotide polymorphisms (SNPs) of this gene with kidney calcium stone in Iranian population. Patients and Methods: Seventy-nine patients with renal stone who underwent PCNL or open surgery were enrolled. Blood samples from each patient and his/her parents were taken and DNA extraction was done using salting out and phenol-chloroform extraction protocols. Genotypes for the MGP T-138C and G-7A polymorphism were determined by PCR-sequencing methods. Statistical analysis and transmission disequilibrium test were done by SPSS software. Results: Total of 235 DNAs were extracted. The most frequent nucleotide is G (67%) in G-7A SNP and T (69%) in T-138C SNP. The CA haplotype was not seen in observed population and other haplotypes had same frequencies. No over transmission of alleles in two SNPs and no association of MGP Polymorphisms and nephrolithiasis were observed. Conclusion: This study is the first family based investigation in Iranian population, which shows, no specific pattern of transmission and no effect of inherited SNPs on stone formation.