Bartter Syndrome
Overview
Plain-Language Overview
Bartter Syndrome is a rare inherited disorder that affects the kidneys, specifically the way they handle salt and minerals. It causes the kidneys to lose too much salt, leading to imbalances in important electrolytes like potassium and chloride. This can result in symptoms such as muscle weakness, cramps, and excessive urination. The condition primarily impacts the renal tubules, which are responsible for reabsorbing salt and water back into the body. Because of these losses, people with this syndrome often have low blood pressure and may feel tired or dehydrated. The disorder usually begins in childhood but can vary in severity. Overall, it disrupts the body's ability to maintain proper fluid and electrolyte balance.
Clinical Definition
Bartter Syndrome is a group of autosomal recessive disorders characterized by defective salt reabsorption in the thick ascending limb of the loop of Henle. The core pathology involves mutations in genes encoding transporters such as the Na-K-2Cl cotransporter (NKCC2), ROMK potassium channel, or CLC-Kb chloride channel, leading to impaired sodium, potassium, and chloride reabsorption. This defect causes hypokalemia, metabolic alkalosis, and hyperreninemic hyperaldosteronism with normal to low blood pressure. The syndrome mimics chronic use of loop diuretics and results in increased distal sodium delivery, stimulating aldosterone secretion and potassium wasting. Clinically, patients present with polyuria, polydipsia, muscle weakness, and growth retardation in severe cases. The condition is significant due to its impact on electrolyte homeostasis and potential for life-threatening complications if untreated.