Gitelman syndrome

Gitelman syndrome is an autosomal recessive disorder of the kidney tubules and the most common inherited salt-losing tubulopathy. It is marked by low blood levels of potassium and magnesium, reduced calcium in the urine and raised blood pH. It results from disease-causing variants in both copies of the SLC12A3 gene, which codes for the thiazide-sensitive sodium-chloride cotransporter found in the distal convoluted tubule of the kidney. Loss of that transporter reduces sodium and chloride reabsorption and produces an electrolyte imbalance much like the one caused by thiazide diuretic drugs. The condition was formerly grouped as a subset of Bartter syndrome until the separate genetic and molecular bases of the two disorders were identified.