Joubert syndrome is a rare genetic condition that causes underdevelopment in a part of the brain called the cerebellar vermis and malformation of the brainstem.
The cerebellar vermis coordinates movements of your head, trunk, and upper limbs. The brain stem controls functions like breathing, blood pressure, and heart rate. Joubert syndrome affects both.
Joubert syndrome goes by several other names:
- Joubert-Bolthauser syndrome
- cerebellooculorenal syndrome 1
- cerebelloparenchchymal disorder IV familial
We examine Joubert syndrome in more depth, including its symptoms, causes, and outlook.
The National Organization for Rare Disorders estimates that Joubert syndrome develops in 1 in 80,000 to 1 in 100,000 live births.
Researchers have found it to occur in about
Most signs and symptoms of Joubert syndrome appear in infancy. They can range from mild to severe.
Signs and symptoms include:
- decreased muscle tone and control
- atypical tongue movement
- sleep apnea
- rapid breathing
- an inability to coordinate muscle movements
- intellectual disability
- seizures
- kidney or liver abnormalities
- physical differences, such as:
- extra fingers and toes (polydactyly)
- cleft lip or palate
- a gap in the skull
- hormonal problems
- tongue abnormalities
- eye problems, such as:
- atypical development of the retina or iris
- abnormal eye movements
- crossed eyes
- drooping eyelids
What are the behaviors of a person with Joubert syndrome?
People with Joubert syndrome
- attention control
- emotional control
- psychosis
- social skills
In
- The first brother had auditory and visual hallucinations that resulted in multiple hospitalizations.
- The second brother had depression and general anxiety disorder.
- The third brother was hospitalized twice in his 20s for:
- auditory hallucinations
- delusions of grandeur
- unprovoked aggression
- suicidal depression
All three brothers had:
- a history of behavioral and emotional dysregulation
- intellectual disability
- coloboma, a hole in one of the structures of the eye
Subtypes of Joubert syndrome
Joubert syndrome can be divided into subtypes depending on the major features. Subtypes include:
| Subtype | Feature |
|---|---|
| Classic Joubert syndrome | • problems with eye movement • breathing problems • extra fingers or toes |
| Joubert syndrome with retinal disease | • retina problems |
| Joubert syndrome with renal disease | • kidney problems |
| Joubert syndrome with oculorenal disease | • retina and kidney problems |
| Joubert syndrome with hepatic disease | • liver problems |
| Joubert syndrome with oral-facial-digital features | • cleft lip and palate • tongue problems • extra fingers or toes |
| Joubert syndrome with acrocallosal features | • atypical development of the tissue that connects the left and right sides of the brain |
| Joubert syndrome with Juene asphyxiating dystrophy | • extra fingers or toes • narrow rib cage • short stature |
Joubert syndrome can develop due to gene mutations inherited from birth parents or from gene mutations that develop sporadically.
Mutations in more than
Some of the most common causes include mutations in:
- AHI1
- CEP290
- NPHP1
Joubert syndrome is particularly common in certain groups, including:
- French Canadians
- Ashkenazi Jews
- Hutterites
Males develop Joubert syndrome about
Joubert syndrome inheritance
Most of the genes associated with Joubert syndrome are recessive, meaning you need to inherit one associated gene from each parent to develop Joubert syndrome.
One rare mutation on the OFD1 gene associated with Joubert syndrome is found on the X chromosome. Females have two X chromosomes and males have one.
Females carrying this OFD1 gene mutation have a 25% chance of having:
- a daughter who carries the gene
- a daughter who doesn’t carry the gene
- a son who has Joubert syndrome
- a son who doesn’t have Joubert syndrome
Males with this gene have a 100% chance of passing Joubert syndrome to their daughters and a 0% chance of passing it to their sons.
Joubert syndrome is a genetic condition. There’s currently no known way to prevent it.
The following three criteria need to be met to diagnose Joubert syndrome:
- A molar tooth sign on an MRI. This is when doctors can see your cerebellar vermis is absent and your brainstem is atypical. On an MRI, a healthcare professional will see a pattern resembling a tooth.
- Weak muscle tone (hypotonia) occurs in infancy, with later issues with coordination (ataxia).
- Developmental delays or intellectual delays are present.
A blood test can also show if you have genes associated with Joubert syndrome.
Joubert syndrome doesn’t currently have a cure. Treatments revolve around managing the health problems that may develop.
Potential treatment options include:
- occupational therapy
- physical therapy
- speech therapy
- annual screening for liver disease, kidney disease, and retinal problems
- oxygen or other treatments to improve breathing
- educational support
- feeding with a gastrostomy tube
- surgery for physical differences
- corrective lenses for eye problems
- dialysis or kidney transplant
The life expectancy for people with Joubert syndrome depends on the severity of the disease. Some people live into adulthood.
In a
This is a serious, life altering condition.
Finding out that your child has Joubert syndrome can be difficult. You may worry about how it will affect their health and quality of life.
You’re not alone in this. The Joubert Syndrome & Related Disorders Foundation is a volunteer-run nonprofit that provides resources and support for parents of children with Joubert syndrome.
Enrolling your child in clinical trials can help researchers improve their understanding of the disease. You can find a list of current clinical trials from the National Library of Medicine website.
Joubert syndrome can lead to many different problems, such as retinal issues, physical changes and differences, and intellectual disability.
The outlook for children with Joubert syndrome varies depending on the severity of their disease. Children with mild disease may live into adulthood.