Magnesium, a cofactor of many enzymes in human body, is involved in major cellular events such as energy metabolism, DNA transcription and protein synthesis. Abnormal levels of magnesium affect many organs in our body and can result in fatal complications. Therefore regulation of plasma magnesium concentration is vital. Plasma magnesium concentration can vary between 1.7 and 2.3 mg/dl. Magnesium homeostasis is regulated with bones, kidneys and bowels. 30-50% of dietary magnesium is absorbed from intestines. It is mainly absorbed in distal small intestine and colon. 95% of magnesium filtered by the kidneys is reabsorbed. 10-25% of filtered magnesium is reabsorbed from proximal tubules via passive paracellular transport. 70% of it is reabsorbed from the loop of henle via paracellular transport by means of positive voltage in lumen. The main storage of magnesium in the body is the bone tissue. In case of hypomagnesemia, osteoclastic activity rises in order to maintain normal magnesium levels. Hereditary hypomagnesemia is consisted of genetic diseases causing primary or secondary renal magnesium losses. These diseases can be evaluated in two groups according to the place of magnesium absorption. Familial hypomagnesemic, hypercalciuria, and nephrocalcinosis and Bartter Syndrome develop as a result of the malabsorption of magnesium in the thick ascending limb of Henle's loop. Hypomagnesemia with secondary hypocalcemia, isolated autosomal recessive hypomagnesemia, isolated autosomal dominant hypomagnesemia, Gitelman syndrome, HNF? nephropathy, East / Se Same Syndrome findings occur as a result of malabsorption of magnesium in distal convoluted tubule. This Article provides information for the diagnosis, clinical findings and the treatment of inherited diseases characterized by hypomagnesemia.İnsan vücudunda birçok enzimin kofaktörü olan magnezyum, enerji metabolizması, DNA transkripsiyonu, protein sentezi gibi major hücresel olaylara katılır. Magnezyum homeastazında barsaklar, kemik ve böbrekler rol alır. Diyetle alınan magnezyumun, yaklaşık %30-50' si barsaklardan emilir. Emilim başlıca distal ince barsak ve kolonda olur. Böbreklerden filtre olan magnezyumun da, %95'i geri reabsorbe olur. Magnezyumun %1025 pasif parasellüler transport ile proksimal tubülden reabsorbe olurken %70'i henlenin çıkan kolunda lümen pozitif voltaja bağlı ve parasellüler olarak gerçekleşir. Vücutta en büyük magnezyum deposu kemik doku ise, hipomagnezemi durumunda osteoklastik aktiviteyi arttırararak magnezyum dengesini sürdürmeye çalışır. Kalıtsal hipomagnezemi, primer ya da sekonder olarak renal magnezyum kaybına neden olan genetik hastalıklardan oluşur. Bu hastalıklar magnezyum emilimimin yapıldığı anatomik bölgeye göre iki grupta değerlendirilebilir. Henle kulbu kalın çıkan kolunda magnezyum emilimi bozukluğu sonucu familyal hipomagnezemik, hiperkalsiüri, nefrokalsinozis ve Bartter Sendromu gelişir. Distal kıvrımlı tübülde magnezyum emilim bozukluğu sonucunda ise, sekonder hipokalsemi ile birlikte hipomagnezemi, izole otozomal resesif hipomagnezemi, izole otozomal dominant hipomagnezemi, Gitelman Sendromu, HNF1? Nefropatisi, East/Se Same Sendromu bulguları oluşur. Bu yazıda hipomagnezemi ile seyreden kalıtsal hastalıkların, tanısı, klinik bulguları ve tedavisi hakkında bilgi verildi
