Canavan disease is classified as a leukodystrophy—a group of inherited neurological disorders that affect the growth of the myelin sheath.
A mutation in the gene which directs the production of the enzyme aspartoacylase (ASPA) allows the buildup of N-acetylaspartic acid (NAA) in the brain. The buildup of NAA causes damage to myelin, a type of fat that surrounds nerve fibers (or axons) in the brain and spinal cord, forming a protective coating that ensures that nerve impulses are properly transmitted from one part of the body to another.
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