Inactivating mutations in NCC (gene name: SLC12A3) result in Gitelman’s syndrome, a salt-wasting tubulopathy with hypokalemia, hypomagnesemia, metabolic alkalosis, and often (but not always) low blood pressure resulting from impairment in Na+ reabsorption [55, 98]. This evidence concerns the gene SLC12A3 and familial primary hypomagnesemia.