ConditionKidneys & urinary tract
Gitelman Syndrome
Gitelman syndrome is an inherited kidney disorder in which the kidneys cannot properly reabsorb salt, leading to low potassium, low magnesium and low calcium in the urine. It is caused by changes in the SLC12A3 gene and is usually diagnosed in teenagers or adults, sometimes after a routine blood test. Symptoms include muscle cramps, weakness, tiredness, salt craving and tingling, though some people have few symptoms. It is lifelong but manageable with potassium and magnesium supplements and a salt-rich diet.
Also called: Gitelman's syndrome, familial hypokalemia-hypomagnesemia, Gitelman variant of Bartter syndrome (older term)
At a glance
- What it is
- A recessively inherited salt-wasting disorder of the kidney's distal tubule.
- Gene
- SLC12A3, which makes the thiazide-sensitive sodium-chloride transporter.
- Lab hallmarks
- Low potassium, low magnesium, metabolic alkalosis, low urine calcium, normal or low blood pressure.
- Symptoms
- Cramps, weakness, tiredness, salt craving, tingling, palpitations; sometimes none.
- Treatment
- Lifelong potassium and magnesium supplements, liberal salt, and sometimes potassium-sparing medicines.
When to get help
Call 911 or go to the ER
- Severe muscle weakness or paralysis, fainting, or a very fast or irregular heartbeat
- Seizures or spasms of the hands and feet (tetany)
See a doctor within a day or two
- Vomiting or diarrhea in someone with Gitelman syndrome, which can rapidly lower potassium and magnesium
- New palpitations or dizziness, especially after starting a new medicine
- Pregnancy in someone with Gitelman syndrome, which needs closer monitoring
Book a routine appointment
- Low potassium found on a blood test without an obvious cause such as diuretics or vomiting
- Recurrent muscle cramps, tiredness and salt craving
- Joint pain and swelling in an adult with long-standing low magnesium (possible chondrocalcinosis)
What happens in Gitelman syndrome
In the distal convoluted tubule of the kidney, a transporter called NCC (the sodium-chloride cotransporter) reabsorbs salt. In Gitelman syndrome, faulty copies of the SLC12A3 gene from both parents make this transporter work poorly. The effect is similar to taking a thiazide diuretic every day:
- salt is lost in the urine, so the body activates hormones (renin and aldosterone) to hold on to salt
- potassium is lost, causing hypokalemia
- magnesium is lost, causing hypomagnesemia
- calcium is retained, so urine calcium is low
- blood becomes slightly alkaline (metabolic alkalosis)
- blood pressure is normal or low
It affects about 1 in 40,000 people, making it one of the more common inherited kidney tubule disorders. Many carriers have one faulty copy and no symptoms.
Symptoms
Symptoms vary widely, even within the same family:
- muscle cramps, spasms and weakness
- tiredness and reduced exercise tolerance
- salt craving
- thirst and frequent urination, including at night
- tingling or numbness, especially around the mouth and fingers
- palpitations
- dizziness, particularly on standing
- joint pain from calcium pyrophosphate deposits (chondrocalcinosis) in adults
- in children: delayed growth or puberty in some cases
Some people are diagnosed only after a routine blood test shows low potassium.
Gitelman vs Bartter syndrome
| Feature | Gitelman syndrome | Bartter syndrome |
|---|---|---|
| Usual age at diagnosis | Teens and adults | Before birth to early childhood (classic forms often later) |
| Kidney segment affected | Distal convoluted tubule | Loop of Henle |
| Urine calcium | Low | Normal or high |
| Blood magnesium | Low | Usually normal |
| Kidney stones or calcification | Rare | Common in some types |
| Severity | Usually milder | Often more severe |
| Mimics | Thiazide diuretic | Loop diuretic |
Diagnosis
- Blood tests: low potassium and magnesium, high bicarbonate (alkalosis), high renin and aldosterone.
- Urine tests: high potassium and chloride loss despite low blood levels; low urine calcium.
- Excluding other causes: hidden vomiting, laxative or diuretic use, which can look identical. A urine diuretic screen may be done.
- Genetic testing: confirms the diagnosis by finding two disease-causing SLC12A3 variants.
- ECG: to check for QT prolongation and arrhythmias.
Treatment
There is no cure, but treatment controls symptoms well.
- Liberal salt intake: encouraged rather than restricted.
- Magnesium supplements: usually given first, because low magnesium makes potassium harder to correct. Slow-release forms cause less diarrhea; doses are divided through the day.
- Potassium chloride supplements: taken with food in divided doses.
- Potassium-sparing medicines: spironolactone, eplerenone or amiloride in some people, with care because of low blood pressure.
- NSAIDs: sometimes used in children with severe symptoms, with monitoring.
Targets are usually a potassium of about 3.0 mmol/L and magnesium of about 0.6 mmol/L, as normal levels are often not achievable.
Day-to-day management
- Eat potassium-rich foods such as bananas, potatoes, beans, tomatoes and dried fruit.
- Increase supplements during vomiting, diarrhea or heavy sweating, guided by your care team.
- Avoid medicines that prolong the QT interval or lower potassium further, unless your doctor approves; carry a list of your diagnosis and medicines.
- Have regular blood tests.
Complications
- dangerous heart rhythms from very low potassium or magnesium, particularly with QT-prolonging drugs
- chondrocalcinosis and joint pain
- reduced quality of life from fatigue
- rarely, chronic kidney disease or impaired glucose tolerance
Outlook
Most people with Gitelman syndrome live normal lifespans. Fatigue and cramps can persist despite treatment. Pregnancy is usually successful but needs closer monitoring because supplement needs rise.
Frequently asked questions
What is Gitelman syndrome?
Gitelman syndrome is an inherited kidney disorder in which salt is lost in the urine, leading to low potassium and magnesium, alkaline blood and low urine calcium. It is caused by changes in the SLC12A3 gene and is usually diagnosed in teenagers or adults.
What are the symptoms of Gitelman syndrome?
Typical symptoms are muscle cramps and weakness, tiredness, salt craving, thirst, frequent urination, tingling and palpitations. Some people have no symptoms and are diagnosed after a routine blood test shows low potassium.
How is Gitelman syndrome treated?
Treatment includes a salt-rich diet and lifelong magnesium and potassium supplements, sometimes with potassium-sparing medicines such as spironolactone or amiloride. Regular blood tests help adjust doses.
Is Gitelman syndrome serious?
Most people have a normal life expectancy, but it can affect quality of life. The main serious risk is abnormal heart rhythms from very low potassium or magnesium, especially during vomiting, diarrhea or with certain medicines.
How is Gitelman syndrome inherited?
It is autosomal recessive. A person must inherit a faulty SLC12A3 gene from each parent. Parents are usually healthy carriers. Each child of two carriers has a 1 in 4 chance of having the syndrome.
Sources
This guide was written from current patient and clinical guidance, including:
- KDIGO: Gitelman syndrome - consensus and guidance from a Controversies Conference
- NORD: Gitelman syndrome
- MedlinePlus Genetics: Gitelman syndrome
- Genetic and Rare Diseases Information Center (GARD): Gitelman syndrome
- Orphanet: Gitelman syndrome