GENETICS AND MOLECULAR BIOLOGY OF RENAL STONES

Genetic studies of calcium kidney stones have hitherto assessed single candidate genes by testing for linkage disequilibria or associations between a locus and stone disease. They have identified the potential involvement of the calcium-sensing receptor (CaSR), vitamin D receptor, (VDR), and bicarbonate-sensitive adenylyl cyclase genes. In addition to research in humans, studies on different strains of knock-out mice have enabled us to include the phosphate reabsorption carrier NPT2 gene, the caveolin-1 gene, the protein NHERF-1 gene modulating calcium and urate reabsorption, osteopontin, and Tamm–Horsfall protein among the possible determinants. Interactions between genes, and between environmental factors and genes, are generally considered fundamental to calcium stone formation, however. To date, therefore, genetic studies have failed to significantly advance our understanding of the causes of calcium kidney stones, though they have enabled us to assess the dimension of the problem and establish criteria for facing it. Further progress in our knowledge of what causes calcium stones may derive from using the tools afforded to researchers by modern biotechnology and bioinformatics.