Canavan disease

What is Canavan Disease?

Canavan disease is an inherited condition that destroys the white matter that insulates nerve cells in the brain. This impairs the ability of nerve cells to communicate with other cells. Canavan disease is caused by harmful genetic changes in the ASPA gene that result in deficiency of the aspartoacylase enzyme. This enzyme breaks down a material called N-acetyl-L-aspartic acid (NAA) in the brain. Without enough aspartoacylase, the NAA builds up in the brain and destroys its white matter.

Neonatal/Infantile Form

Neonatal/infantile Canavan disease is the most common form of Canavan disease. Affected children develop muscle weakness, developmental delay, and severe intellectual disability. Developmental delays typically begin at three to five months of age with poor muscle tone (hypotonia) which causes problems with an infant's ability to turn over, control head movements, and sit up. The infant's head also becomes larger (macrocephaly). Over time, children with the condition may become unable to swallow and may develop sleep disturbances, seizures, and blindness.

Mild/Juvenile Form

Individuals with the mild/juvenile form of Canavan disease may have mild speech or motor delays beginning in childhood. However, for some affected individuals, the delays may be so mild that they go unrecognized or so nonspecific that affected individuals may be undiagnosed.

How common is Canavan Disease?

The incidence of the neonatal/infantile form of Canavan disease in the population is 1 in 100,000 births. The incidence of the mild/juvenile form of Canavan disease is unknown. The incidence of Canavan disease is more common among individuals of Ashkenazi Jewish descent.

How is Canavan Disease treated?

Currently, there is no cure for Canavan disease. Treatment for the neonatal/infantile form of the disease focuses on keeping the affected individual comfortable with proper nutrition and hydration and controlling seizures with medication. Physical therapy can be beneficial to maximize ability and to minimize tightening of muscles. Individuals with the mild/juvenile form of Canavan disease may need speech therapy or tutoring but generally do not require special medical care.

What is the prognosis for an individual with Canavan Disease?

Most individuals with the neonatal/infantile form of Canavan disease die in childhood, although some survive into their teens or early twenties and beyond, depending on the medical care provided. Individuals with the mild/juvenile form of the disease do not typically have a shortened lifespan.