<prompt> Not a cause of Hypomagnesemia:Gitelman syndromeRe-feeding syndromeHyperaldosteronismRhabdomyolysis  <response>: Gitelman is a defect of DCT where TRPM6 receptor for magnesium reabsorption is present and is defective leading to Hypomagenesemia In Re-feeding syndrome seen with starvation, provision of nutrition in form of substrates will lead to cellular consumption leading to rapid shift of magnesium from extracellular fluid to intracellular compaments. Hyperaldosteronism will lead to expansion of plasma volume and resultant fall of magnesium. In Rhabdomyolysis cell destruction will lead to Hypermagnesemia. 