Gitelman syndrome (GS) is an autosomal recessive kidney tubule disorder characterized by low blood levels of potassium and magnesium, decreased excretion of calcium in the urine, and elevated blood pH. The disorder is caused by genetic mutations resulting in improper function of the thiazide-sensitive sodium-chloride symporter (SLC12A3, also known as NCC, NCCT, or TSC) located in the distal convoluted tubule of the kidney. The distal convoluted tubule of the kidney plays an important homoestatic role in sodium and chloride absorption as well as of the reabsorption of magnesium and calcium.Genetic mutations of NCC, lead to loss of function and subsequently, reduced transport of sodium and chloride via NCC. Secondary derangement of calcium, magnesium, and potassium concentrations are caused by secondary effects in the distal tubule and collecting duct. The effect is an electrolyte imbalance similar to that seen with thiazide diuretic therapy (which causes pharmacological inhibition of NCC activity).Gitelman syndrome was formerly considered a subset of Bartter syndrome until the distinct genetic and molecular bases of these disorders were identified. Bartter syndrome is also an autosomal recessive cause of hypokalemic metabolic alkalosis, but it derives from a mutations of a number of genes that reduce NKCC2 activity. NKCC2 is found in the thick ascending limb of the loop of Henle. Signs and symptoms
Affected individuals may not have symptoms in some cases.
Primary aldosteronism will cause metabolic alkalosis and hypokalaemia, but hypertension will be present and serum renin will be low
EAST syndrome, though neurological features will predominate
Renal cysts and diabetes syndrome can cause hypomagnesaemia and hypocalcuria, but is distinguished by early onset chronic kidney disease and an autosomal dominant inheritance pattern of renal cysts and/or diabetes

Treatment
Most asymptomatic individuals with Gitelman syndrome can be monitored without medical treatment. Dietary modification of a high salt diet incorporated with, potassium and magnesium supplementation to normalize blood levels is the mainstay of treatment. Large doses of potassium and magnesium are often necessary to adequately replace the electrolytes lost in the urine. Diarrhea is a common side effect of oral magnesium which can make replacement by mouth difficult but dividing the dose to 3-4 times a day is better tolerated. Severe deficits of potassium and magnesium require intravenous replacement. If low blood potassium levels are not sufficiently replaced with replacement by mouth, aldosterone antagonists (such as spironolactone or eplerenone) or epithelial sodium channel blockers such as amiloride can be used to decrease urinary wasting of potassium.In patients with early onset of the disease such as infants and children, indomethacin is the drug of choice utilized to treat growth disturbances. Indomethacin in a study by Blanchard et al. 2015 was shown to increase serum potassium levels, and decrease renin concentration. Adverse effects of indomethacin include a decrease in the glomerular filtration rate, and gastrointestinal disturbances.Cardiac evaluation is promoted in the prevention of dysrhythmias and monitoring of QT interval activity.