Joubert Syndrome - Jewish Genetic Disease

Description
Joubert Syndrome is an autosomal recessive genetic disorder that is characterized by the underdevelopment or absence of the cerebral vermis. The cerebral vermis is a thin worm shaped structure located between the two hemispheres of the cerebellum. The cerebellum, Latin for “little brain” is the area of the hindbrain that is responsible for controlling coordination, balance and equilibrium as well as skeletal muscle tone.

Symptoms
   •   Decreased muscle tone
   •   Difficulty swallowing
   •   Jerky eye movements (nystagmus)
   •   Periods of hyperpnea – rapid breathing- may seem like panting
   • Inability to coordinate voluntary muscle movement
   • Poor mental development
   • Large toes and fingers or polydactyly- extra fingers or toes
   • Abnormalities in the shape of the tongue or cleft lip or palate
   • Abnormal growth of the retina
   • Seizures may occur
   • Kidney failure – as they grow older .

Incidence and Carriers
One specific mutation found in the TMEM216 gene on chromosome #11 was found to occur in approximately 1 in 92 Ashkenazi Jewish individuals. This incidence translates to one in every 8,000 Ashkenazi Jewish couple may conceive a child with Joubert Syndrome. Testing for one common mutation provides a carrier detection rate of at least 95% in this population.

Joubert syndrome affects approximately one in 100,000 children — which equals to about 40 babies per year in the United States

Treatment
There is not cure for Joubert Syndrome. Treatment is supportive and symptomatic.
Treatment includes the following:
   •   Infant stimulation
   •   Physical therapy
   •   Occupational therapy
   •   Speech therapy
   •   Monitoring of respiratory status with infants who have breathing abnormalities
   •   Screening for progressive eye, liver, and kidney complications done on a regular basis
   •   Unconventional therapies such as sensory integration, auditory training, water therapy and horseback therapy have been found to be beneficial.

Testing
Although genetic tests can identify a particular causative gene, they often can not predict the severity of the disease.

Genetic testing for Joubert Syndrome is difficult and costly. Cost for this genetic testing can range between $200 - $6,000 which may or may not be covered by medical insurance. Currently it is believed that less than 40% of individuals with Joubert Syndrome will have a mutation identified in one of the 5 known genes.
In Ashkenazi Jews one specific mutation was found in the TMEM216 gene on chromosome #11.

Resources and More

Laboratories In the United States
Emory University School of Medicine
Emory Molecular Genetics Laboratory
Atlanta, GA
(404) 778-8500
fax: (404) 778-8559
email: eglgc@emory.edu
Mailing Address
Emory Genetics Laboratory
2165 N. Decatur Road
Decatur, GA 30033

PreventionGenetics
3700 Downwind Drive
Marshfield, Wisconsin 54449 USA
Phone: 715-387-0484
Fax: 715-384-3661

Laboratories In Israel
Ha’Emek Medical Center , Molecular Genetics Unit
Ha’Emek Medical Center , Institute of Genetics ,
Afula 18101 , Israel
Telephone: (+972)-4-6495416

Sheba Medical Center; The Danek Gertner Institute Human Genetics; Molecular diagnosis Laboratory
Tel Hashomer; Ramat Gan . 52621, Israel
Telephone: (+972)-3-5303060
Web: http://www./eng.sheba.co.il

The Simon Winter Institute for Human Genetics, The Bnai Zion Medical Center
47 Eliyahu Golomb, Haifa , 33394
Telephone: (+972)-4-835-9851, (+972)-4-835-9495
Web: http://www.b-zion.org.il

SUPPORT GROUPS
http://health.groups.yahoo.com/group/joubertsyndrome
Joubert Syndrome Foundation
President Cheryl Duquette
6931 South Carlinda Avenue
Columbia, MD 21046
Phone: 410-997-8084
E-mail: joubert@joubertsyndrome.org
Web site: www.joubertsyndrome.org