Gitelman syndrome

A diagnosis of Gitelman syndrome may be suspected in children and adults with characteristic symptoms. A number of blood and urine tests aid in the diagnosis of Gitelman syndrome, such as:

Potassium urine test
Blood gases
Blood tests to measure magnesium, aldosterone, and renin
Urine analysis for sodium, potassium, and calcium

Common blood and urine abnormalities found in Gitelman syndrome, include:

Low levels of potassium in the blood (hypokalemia)
Metabolic alkalosis (too much base in the body)
Low magnesium in the blood (hypomagnesemia)
Low levels of calcium in the urine (hypocalciuria)

Anorexia, bulimia, chronic diarrhea, vomiting, and long term use of laxatives or diuretics can cause similar signs and symptoms. Before a diagnosis of Gitelman syndrome is made these conditions must be ruled out. A careful review of the patient and family health histories, as well as renal ultrasound findings can be helpful in ruling out other causes.

Genetic testing can confirm a diagnosis of Gitelman syndrome. Tools for finding genetic testing for Gitelman syndrome are available below.

Gitelman syndrome is inherited in an autosomal recessive manner. This means that to be affected, a person must have a mutation in both copies of the responsible gene in each cell. Affected people inherit one mutated copy of the gene from each parent, who is referred to as a carrier. Carriers of an autosomal recessive condition typically do not have any signs or symptoms (they are unaffected). When 2 carriers of an autosomal recessive condition have children, each child has a:

• 25% (1 in 4) chance to be affected
• 50% (1 in 2) chance to be an unaffected carrier like each parent
• 25% chance to be unaffected and not be a carrier

The long-term outlook (prognosis) for people with Gitelman syndrome is generally very good. However, the symptoms and severity can vary from person to person. Some people do not develop any symptoms, while others develop chronic issues that can impact their quality of life. Weakness, fatigue and muscle cramping can affect daily activities in some people with Gitelman syndrome. In general, while the underlying condition does not appear to be progressive, complications can arise, especially if care recommendations are not followed.

Progressive renal insufficiency is extremely rare. Renal function is usually maintained despite long-term hypokalemia (low potassium), but progression to chronic renal insufficiency has rarely been reported.

Some people with Gitelman syndrome may be at risk of developing cardiac arrhythmias. Those with severe hypokalemia are more susceptible to cardiac arrhythmias, which can be life-threatening when joined with severe hypomagnesemia (low magnesium) and alkalosis. Therefore, an in-depth cardiac work-up is strongly recommended to identify which people with Gitelman syndrome may be at risk. Competitive sports should be avoided because sudden death can be precipitated by intense physical activity that induces potassium and magnesium loss by sweating.

The mainstay treatment of Gitelman syndrome involves careful monitoring, high- sodium and potassium diet, and oral potassium and magnesium supplements. Intravenous magnesium and/or potassium may be needed if symptoms are severe. People who have low potassium levels despite supplementation and diet, may benefit from potassium-sparing diuretics, renin angiotensin system blockers, pain medications, and/or nonsteroidal anti-inflammatory drugs (NSAIDs).

The Blanchard A et al., 2017 consensus guideline offers detailed treatment information, including information on drug selection, dosing recommendations, and a listing of drugs that can cause adverse effects in people with Gitelman syndrome.

Lastly, people with Gitelman syndrome should have a thorough heart work-up. People with Gitelman syndrome and a prolonged QT interval should avoid drugs that prolong the QT interval. The SADS Foundation offers a tool for learning more about what drugs to avoid.