TRPV6 and Hypercalciuria: Thus, genome-wide association studies, aiming to reveal gene variants contributing to polygenic traits,in Icelandic and Dutch populations identified susceptibility risk variants in the claudin 14 (CLDN14) gene for hypercalciuric nephrolithiasis, [10] and a study of Swiss renal calcium stone formers has reported an association between an ancestral haplotype defined by the non-synonymous polymorphisms of the transient receptor potential cation channel, subfamily V, member 6 (TRPV6), which resulted in a gain-of-function and absorptive hypercalciuria [11].