Canavan disease is a rare, inherited, neurological disorder characterized by spongy degeneration of the brain (in which the white matter is replaced by microscopic fluid-filled spaces). It is caused by a deficiency of an enzyme called aspartoacylase. Canavan disease is one of a group of genetic disorders called the leukodystrophies that affect growth of the myelin sheath of the nerve fibers in the brain. The myelin sheath is the fatty covering surrounding nerve cells that acts as an insulator. Symptoms of Canavan disease, which appear in early infancy and progress rapidly, may include mental retardation, loss of previously acquired motor skills, feeding difficulties, abnormal muscle tone (i.e., floppiness or stiffness), poor head control, and megalocephaly (abnormally enlarged head). Paralysis, blindness, or hearing loss may also occur. Although Canavan disease may occur in any ethnic group, it affects persons of Eastern European Jewish ancestry more frequently.
There is no cure for Canavan disease, nor is there a standard course of treatment. Treatment is symptomatic and supportive. The prognosis for Canavan disease is poor. Death usually occurs before age 10.
