Joubert Syndrome

What is Joubert syndrome?

Joubert syndrome is a rare brain condition. It affects the back of the brain, which helps control balance and coordination.  On magnetic resonance imaging (MRI) scans, changes to the brain look like a person’s back tooth, which is why it is called the “molar tooth sign.”

Variants (also called mutations) in a group of specific genes cause Joubert syndrome. Joubert syndrome is autosomal, which means the gene variants that cause it are on non-sex chromosomes. It can pass down in families in different ways.

In most cases, Joubert syndrome is inherited in an autosomal recessive pattern. This means a person must inherit two copies of the affected gene, one from each parent, to have the disease. The parents of a person with an autosomal recessive condition each carry one copy of the altered gene, but they typically don’t show signs and symptoms of the condition.

Sometimes, Joubert syndrome can happen because of other inheritance patterns. Specific variants may happen more frequently in certain ethnic groups.

Symptoms of Joubert syndrome

People with Joubert syndrome have a molar tooth sign, weak or floppy muscles (hypotonia), and take longer to learn skills like sitting, walking, or talking early in life. Other symptoms and signs can include:

• Eye movements that are hard to control
• Learning and thinking problems
• Muscle movements that are hard to control (ataxia)
• Unusually fast breathing (hyperpnea)
• Certain physical features such as a broad forehead, extra fingers or toes, a cleft lip or palate (opening in the top of the mouth), and differences in the shape and function of the tongue
• Kidney and liver problems
• Seizures

People with Joubert syndrome have different symptoms depending on how much of their brain and other body parts are affected.  Some people have mild symptoms affecting movement and physical growth. Other people may have more severe symptoms affecting other parts of the body.

How is Joubert syndrome diagnosed and treated?

Diagnosing Joubert syndrome

Doctors usually use MRI scans that show the molar tooth sign to diagnose Joubert syndrome. But they also look for specific symptoms and body features. Genetic testing can help identify variants in genes that cause Joubert syndrome.   

Doctors will perform more tests after diagnosing Joubert syndrome to see which parts of the body are affected. The tests can also identify which treatments may work best. These tests can include:

Learn more about neurological diagnostic tests and procedures.

Treating Joubert syndrome

Because there is no cure for Joubert syndrome, doctors treat the specific symptoms a person with the condition has. Some children may benefit from simple, play-based activities designed to help babies develop movement, senses, communication, and social skills. Other possible treatments include therapy to help children build physical skills and reach their developmental milestones. Doctors often track symptoms of Joubert syndrome through checkups. They also do routine screenings for problems with the eyes, liver, and kidneys.

What are the latest updates on Joubert syndrome?

The National Institutes of Health (NIH), which includes NINDS, is the leading federal funder of research on the brain and nervous system, including disorders such as Joubert syndrome. NIH supports new and innovative research to better understand, diagnose, and treat Joubert syndrome. 

NIH-funded researchers in Philadelphia, PA are currently trying to understand how Joubert syndrome affects kidneys and the liver. They are collecting and safely storing DNA samples from people with the condition to better understand how genetic changes contribute to Joubert syndrome. This research is funded by another NIH Institute—the National Institute of Diabetes, Digestive, and Kidney Diseases (NIDDK).

For more information on research about Joubert syndrome, check NIH RePORTER, a searchable database of current and past research projects funded by NIH and other federal agencies. RePORTER also has links to publications and resources from these projects. 

For research articles and summaries on Joubert syndrome, search PubMed, which contains citations from medical journals and other sites.

How can I or my loved one help improve care for people with Joubert syndrome?

Consider participating in a clinical trial so clinicians and scientists can learn more about Joubert syndrome and related disorders. Clinical research with human study participants helps researchers learn more about a disorder and perhaps find better ways to safely detect, treat, or prevent disease.

All types of participants are needed—those who are healthy or may have an illness or disease—of all different ages, sexes, races, and ethnicities. This helps make sure that study results apply to as many people as possible and that treatments will be safe and effective for everyone who will use them.

For information about participating in clinical research, visit the NINDS Clinical Trials site and NIH Clinical Research Trials and You. Learn about clinical trials currently looking for people with Joubert syndrome at ClinicalTrials.gov, a searchable database of current and past clinical studies and research results.