What is Canavan Disease? Canavan disease is a fatal neurological disorder that deteriorates the white matter in the brain. White matter, or myelin,insulates nerve cells in the brain, much like insulation around a wire. Children with Canavan disease lack an enzyme responsible for breaking down an acid in the brain called NAA. An over accumulation of NAA in the brain hinders the normal formation of myelin.Children born with Canavan disease are incapable of holding up their heads, sitting or even speaking, and may die in early childhood. Many children do live into adolescence and even young adulthood.The Canavan gene has been identified allowing at risk couples to test for this deadly disease. Both parents must be carriers in order to have a child with Canavan (25% risk or 1 in 4).While slightly more prevalent in the Ashkenazi Jewish population, Canavan occurs in people of every ethnic background as well. Expectant couples concerned about risk of carrying the gene for Canavan should seek genetic counseling.