Read on to learn more about the causes, symptoms, diagnostic process, and treatments for Bartter syndrome.
Bartter syndrome results from mutations in the genes responsible for normal kidney function. The condition is classified into five general types, which are caused by mutations in different genes:
- type I
- type II
- type III
- type IV, subdivided into types IVA and IVB
- type V
These genetic mutations cause the kidneys to lose their ability to reabsorb salt. This leads to excess salt being expelled through urine. It also affects the absorption of other electrolytes such as calcium and potassium. These imbalances cause the symptoms of Bartter syndrome.
Inheritance
Bartter syndrome is an autosomal recessive disorder. This means an affected individual receives one mutated gene from each parent.
The symptoms of Bartter syndrome can vary greatly, even in people with the same subtype. Variants in the mutated genes can help explain these differences. Symptoms may start any time from before birth to adulthood.
According to the National Organization for Rare Disorders, common symptoms of Bartter syndrome include:
- muscle weakness
- spasms
- cramping
- fatigue
Symptoms in the period before birth can include excessive urine production and atypical fluid buildup around the fetus. Premature births are more common for infants affected in the uterus.
Newborns may also experience excessive urination, dehydration, and fever. In some cases, infants may have triangular shaped faces and a prominent forehead. They may also have large eyes, pointed ears, and drooping corners of the mouth.
Over time, affected children may experience delays in growth and development. Their adult stature may also be shorter than normal.
Other potential symptoms include:
- irregular heartbeat
- blood in the urine
- vomiting
- kidney stones
- hearing impairment or deafness
- cognitive impairment
- motor difficulties
To diagnose Bartter syndrome, your doctor will assess your medical history and perform a physical exam. They will then typically order lab tests to confirm a diagnosis.
These tests may include:
- blood tests
- urine tests
- radiographs
- intravenous pyelograms, or X-rays of the urinary tract
- kidney ultrasonograms
- CT scans
Certain findings from lab tests can indicate Bartter syndrome, such as:
- hypokalemia, or low potassium levels
- hypochloremia, or low chloride levels
- hyperreninemia, or high renin levels
- hyperaldosteronemia, or high aldosterone levels
- metabolic alkalosis, or excess alkaline levels
In addition, doctors may order genetic tests to confirm or rule out specific genetic mutations.
Treatment for someone with Bartter syndrome can vary depending on the symptoms and the age of onset.
A 2021 expert review makes the following recommendations for treatment during the prenatal and postnatal periods.
Prenatal treatments
More research is necessary to standardize recommendations for treating prenatal Bartter syndrome. However, fetuses experiencing symptoms may benefit from measures to reduce the amount of amniotic fluid.
These measures may involve amniocentesis, which is a procedure to remove fluid with a needle. Additionally, doctors may recommend that the mother take nonsteroidal anti-inflammatory drugs (NSAIDs).
Postnatal treatments
After birth, doctors may recommend various supplements spread throughout the day. These can help restore fluid and electrolyte balance in the body. Postnatal supplements can include:
- salt
- potassium
- magnesium
People with symptoms of Bartter syndrome may also benefit from NSAIDs or gastric acid inhibitors.
In addition, experts note that dietary modifications and adequate hydration can help manage Bartter syndrome symptoms.
A person with Bartter syndrome will require lifelong treatment with medications and supplements. With early diagnosis and treatment, they can lead a relatively normal life.
Without treatment, Bartter syndrome can cause severe complications and even death.
People with Bartter syndrome who experience severe electrolyte imbalances can develop cardiac arrhythmias, or irregular heartbeats. Without treatment, these arrhythmias can lead to cardiac arrest and death.
In addition, untreated Bartter syndrome can lead to chronic kidney disease.
Here are some other frequently asked questions about Bartter syndrome. These answers have been reviewed by Dr. William C. Lloyd III.
What is Pseudo-Bartter syndrome?
Pseudo-Bartter syndrome refers to conditions that cause symptoms similar to Bartter syndrome. The difference between the two is that Pseudo-Bartter syndrome is not characterized by inherited kidney malfunction.
What is the difference between Bartter syndrome and Gitelman syndrome?
While Bartter syndrome and Gitelman syndrome can have similar symptoms, they differ in a few ways.
Bartter syndrome causes excess calcium excretion through the urine, while Gitelman syndrome causes low calcium excretion. The parts of the kidney experiencing dysfunction also differ between the two syndromes.
How common is Bartter syndrome?
Bartter syndrome is less common than Gitelman syndrome. Researchers estimate that it affects around 1 in 1 million individuals.
Is Bartter syndrome serious?
Bartter syndrome can cause serious complications without treatment. By following a strict treatment plan, many people with Bartter syndrome can lead normal lives.
Can Bartter syndrome be cured?
There is currently no known cure for Bartter syndrome. Treatment involves managing the symptoms and preventing complications.
Bartter syndrome is an inherited condition that affects the kidneys. It results from mutations in certain genes that control normal kidney function.
Symptoms can include muscle weakness, cramping, and spasms. Before birth, some fetuses may experience excessive urination, which can result in abnormal amniotic fluid buildup.
Treatment for Bartter syndrome mainly involves addressing the specific symptoms. Doctors may recommend medications and supplements.
Talk with your doctor about ways to manage Bartter syndrome.
