Researchers at the Hadassah University Medical Center, together with Dor Yeshorim (The Committee for the Prevention of Jewish Genetic Diseases) have announced the discovery of a genetic mutation that causes children of Ashkenazi Jews to be born with Joubert Syndrome, a neurological genetic disease. Their findings will be published in the January 2010 edition of The American Journal of Human Genetics. This is the 13th gene whose mutations may cause the birth of children with genetic diseases Hadassah’s Department of Genetics and Metabolic Diseases discovered during the last two years.
Joubert Syndrome is a neurological genetic disease that affects the cerebellum – the "little brain” responsible for controlling balance and coordination of the skeletal muscles. Infants born with this syndrome exhibit decreased muscle tone, difficulty in swallowing, jerky eye movements and the inability to coordinate voluntary muscle movements. As they develop, they may suffer from mental retardation and develop kidney failure.
Concerned with the increasing number of children born with Joubert Syndrome in recent years, Dor Yeshorim asked Hadassah to investigate the cause. An analysis of sick children’s DNA revealed that – although the children were not from the same family – all their DNA had an identical segment that included 14 genes. After testing the 14 gene sequence, the research team identified the one with the mutation that causes Joubert Syndrome.
Based on these initial findings, they examined the DNA of 3,000 healthy Ashkenazi Jews and discovered that one out of 92 Ashkenazi Jews carried the mutation. This means that one of every 8,000 Ashkenazi Jewish couples may have a child with Joubert Syndrome.
The Hadassah research team included Dr. Simon Edwardson, Dr. Avraham Shaag, Dr. Shamir Zenvirt, and Prof. Orly El-Peleg, with the participation of Dor Yeshorim.