Canavan disease is a progressive, fatal neurological disorder that begins in infancy. It is caused by an inherited genetic abnormality: the lack of an essential enzyme causes deterioration of the white matter (myelin) in the brain, thereby preventing the proper transmission of nerve signals.
Symptoms of Canavan disease vary, but generally include rapidly increasing head circumference, lack of head control, reduced visual responsiveness and abnormal muscle tone such as stiffness or floppiness. Children with Canavan disease cannot crawl, walk, sit or talk. Over time they may suffer seizures, become paralyzed, developmentally delayed or blind and have trouble swallowing. Deafness may also result.
Symptoms usually become apparent when the infant is three to nine months old. Many children do not live past age 10. At the present time there is no cure for Canavan disease. Treatment involves managing the symptoms.
Canavan disease is found most often in persons of Ashkenazi (German and Eastern European) Jewish ancestry. It is estimated that 1 in 40 Ashkenazi Jews is a carrier of the Canavan gene. It is also found in other ethnic groups. In fact, thanks to the success of ongoing screening programs in the Jewish population, most of the children born with Canavan disease today have no known Jewish heritage.
The NIH Genetics Home Reference site has further scientific information on Canavan disease with extensive links to other scientific and medical sites.