Deletion of Trpm6 in mice is embryonic lethal, whereas humans with recessive mutations in TRPM6 develop early onset of hypomagnesemia and secondary hypocalcemia, further emphasizing the significance of Mg2+ reabsorption in the DCT (Schlingmann et al., 2002; Walder et al., 2009). This evidence concerns the gene TRPM6 and familial primary hypomagnesemia.