A group of symptoms and signs including enlargement of certain kidney cells, alkalosis associated with reduced potassium (hypokalemic alkalosis), and increased production of the hormone aldosterone (see the aldosterone test). There is no elevation of blood pressure (which usually occurs with kidney disease ).

Alternative Names

Urinary potassium wasting

Causes, incidence, and risk factors

The exact cause of Bartter's Syndrome is not known. In some cases it is genetic. It is thought to be caused by a defect in the kidney's ability to reabsorb potassium. As a result, an excessive amount of potassium is urinated out of the body. This is also known as potassium wasting.

Signs and tests

The diagnosis of Bartter's Syndrome is usually made by finding low levels of potassium in the blood. The potassium level is usually less than 2.5 mEq/L. Other signs of this syndrome include:

Normal blood pressure

Low blood chloride

Metabolic alkalosis (blood is more alkaline that normal)

High blood levels of the hormones renin and aldosterone (both are involved in the regulation of potassium by the kidney)

High levels of potassium and chloride in the urine

These exact signs and symptoms can occur in people who have taken excessive amounts of diuretics or laxatives, and in people who have eaten extremely large amounts of licorice. Urine tests can be done to exclude these. In Bartter's Syndrome, a biopsy of the kidney typically shows overgrowth of cells called the juxtaglomerular apparatus. However, this is not found in all patients, especially in young children.

Treatment

Bartter's Syndrome is treated by keeping the potassium level in the blood above 3.5 mEq/L. This is done through a diet rich in potassium, some patients require salt and magnesium supplements.

Expectations (prognosis)

The long term prognosis for patients with Bartter Syndrome is not certain. It seems infants who start with severe growth failure typically end up growing normally with treatment. Studies are being done to see if these children have decreased mental functioning. While most patients remain well on treatment, some develop kidney failure.

Calling your health care provider

Call your health care provider if your child is not growing well, is urinating frequently, and is having muscle cramps.