Joubert Syndrome

Joubert syndrome is a rare genetic disorder that occurs when parts of the brain don’t develop properly. It affects each child differently, from minor to severe symptoms. It can cause problems with intellectual development, motor skills, eyesight, and kidney or liver function. Joubert syndrome is diagnosed by the “molar tooth sign” on a brain MRI.


Joubert syndrome is a rare disorder in infants and children whose brains don’t develop correctly. A part of the brain called the cerebellar vermis, which controls balance and coordination, is either underdeveloped or absent. And the brain stem, which connects the brain and spinal cord, is also abnormal.

Joubert syndrome can affect many different parts of the body. It can lead to multiple health problems, developmental delays and intellectual disability.

How common is this cerebellar disease?

Joubert syndrome is rare. It’s estimated to affect only about one in 100,000 or more newborns. Only a few hundred cases have been reported in the medical literature.


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Are some people more at risk for Joubert syndrome?

Joubert syndrome runs in families, so people who have relatives with Joubert syndrome have a higher chance of passing it on to their children.

The syndrome is more common in some ethnic groups: Ashkenazi Jewish, French-Canadian and Hutterite.

Symptoms and Causes

What causes Joubert syndrome?

Joubert syndrome is caused by mutations in 35 or more genes. It can be inherited within families or happen by chance (with no known family link).

The genetic mutations cause cilia to form incorrectly. Cilia are like tiny antennas on cells that help them communicate with each other. They help organs develop and function. Joubert syndrome is in a group of disorders called “ciliopathies.”

Researchers are still trying to understand how the abnormal cilia cause the specific developmental problems in Joubert syndrome.


What are the symptoms of Joubert syndrome?

Symptoms of Joubert syndrome can vary quite a lot, even among people in the same family. They can range from a few mild effects to severe problems in multiple body systems.

Depending on what body systems are involved, the condition may be called “Joubert syndrome and related disorders.”

The most common signs in infants are:

  • Abnormal eye movements, such as trouble moving the eyes from side to side.
  • Fast breathing.
  • Delayed intellectual and language development.
  • Inability to control voluntary muscle movements (ataxia), such as walking, picking things up and speaking.
  • Weak muscle tone (hypotonia).

Some people with Joubert syndrome might also have physical deformities, such as:

Joubert syndrome can affect organ systems that depend on cilia, including:

  • Eyes, particularly the retinas.
  • Kidney.
  • Liver.

Diagnosis and Tests

How is Joubert syndrome diagnosed?

Healthcare providers consider the child’s symptoms and MRI to diagnose Joubert syndrome.

In patients with Joubert syndrome, MRI images of the brain will show the “molar tooth sign.” The part of the brain stem that didn’t form correctly tends to look like a molar tooth.

A child is diagnosed with Joubert syndrome if he or she has:

  • Developmental delays or intellectual disabilities.
  • Hypotonia during infancy that develops into ataxia in childhood.
  • Molar tooth sign on MRI.

Management and Treatment

Is there a cure for Joubert syndrome?

There is no cure for Joubert syndrome. But your healthcare providers may recommend treatments to reduce symptoms and improve quality of life.

What treatments will my child with Joubert syndrome need?

Treatment is different in each person, depending on the ways Joubert syndrome affects the individual.

Developmental delays may be treated with:

  • Infant stimulation.
  • Occupational therapy.
  • Physical therapy.
  • Speech therapy.

Depending on the ways Joubert syndrome affects your child, you might need regular visits with specialists such as:

  • Nephrologists, who treat kidney disorders.
  • Neurologists, who specialize in the brain.
  • Ophthalmologists, who treat eye problems.

They will:

  • Monitor how the disorder is affecting those systems.
  • Determine whether the effects on that system are getting worse over time.
  • Offer treatments if available.

In addition, you may talk to geneticists or genetic counselors. They can confirm the specific gene mutations in Joubert syndrome. They also can help families decide who else should be tested for the mutations.


Can I prevent Joubert syndrome?

There is no way to prevent Joubert syndrome. But geneticists and genetic counselors can help determine who in your family may be at risk. That information can help people decide whether to have children, for example.

Outlook / Prognosis

What is the outlook for people with Joubert syndrome?

The outlook for babies and children with Joubert syndrome depends on whether the cerebellar vermis is partially developed or completely absent. It also depends on what other body systems are affected and in what way.

Some children have mild effects, with only minor symptoms and almost normal development. Others experience significant problems with development, severe impairment in function and organ involvement.

Joubert syndrome can be fatal in childhood. Researchers are still studying life expectancy with this rare condition.

Living With

What should I ask my healthcare provider about Joubert syndrome?

Joubert syndrome affects families in different ways. Consider asking your healthcare providers:

  • What disabilities can we expect to see?
  • What is our child’s life expectancy?
  • What specialists do we need to see?
  • How often should we see them?
  • Should other family members get genetic testing?

How can my family learn to cope with Joubert syndrome?

To help you and your family cope with Joubert syndrome, you can try:

  • Counseling.
  • Getting involved with organizations that support patients and research.
  • Support groups.

A note from Cleveland Clinic

Joubert syndrome is a rare genetic disorder that affects development of the brain. It also may affect the eyes, kidney and liver. The syndrome impacts each person differently. Talk to your healthcare provider about the care your child will need and whether family members should be tested.

Medically Reviewed

Last reviewed by a Cleveland Clinic medical professional on 02/10/2021.

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