Gitelman’s syndrome, also known as, familial hypokalemia–hypomagnesemia, is a renal tubulopathy responsible for salt wasting resulting in, hypomagnesemia, hypocalciuria, and secondary activation of the renin–angiotensin–aldosterone system, responsible for the hypokalemia and metabolic alkalosis. The gene discussed is REN; the disease is familial primary hypomagnesemia.