Canavan disease is an inherited disorder that destroys the myelin sheath, the white matter that insulates nerve cells in the brain. It causes overall muscle weakness and developmental delay leading to severe mental disability.
Symptoms usually begin at 3 to 5 months of age with poor muscle tone (hypotonia), which causes problems turning over, controlling head movements, and sitting up. The infant's head also becomes rapidly larger.
Over time, people with the condition become unable to swallow and develop sleep disturbances, seizures, and blindness. Most people with Canavan disease die in childhood, although some have lived into their teens and early twenties.
Canavan disease is caused by a deficiency in an enzyme called aspartoacylase. This enzyme breaks down a material called N-acetyl-L-aspartic acid (NAA) in the brain. Without enough enzyme, the NAA builds up in the brain and destroys its white matter.
At this time, there is no cure for Canavan disease. Treatment mostly aims to ease the symptoms of the disease. Lithium and other drugs are being investigated. Treatment focuses on keeping the affected person comfortable with proper nutrition and hydration and controlling seizures with medication.
Gene replacement therapy seems to show promise for Canavan disease. A recently-completed study in mice, showed slowing of the course of the disease as a result of injecting the aspartoacylase gene into mice bred to have an enzyme deficiency similar to the one that causes Canavan disease in humans.
Despite ongoing research, a cure or effective treatments of Canavan disease are still in the future. Identifying carrier couples and help them find ways to build families free of Canavan disease remain the most practical way to lessen the impact of the disease on carrier families at the current time.
Read more articles on Canavan.