Canavan disease - Prenatal diagnosis and genetic counseling

Canavan disease, also known as spongy degeneration of the brain, is a severe neurodegenerative disease that leads to early death. The disease is caused by deficiency of the enzyme aspartoacylase (ASPA), which causes increased levels of N-acetylaspartic acid (NAA) in brain and excessive excretion in urine. There is no treatment for Canavan disease. Recent developments in carrier identification have led to two major findings: 1) that Canavan is not a rare disease among Ashkenazi Jews and 2) molecular diagnosis of carriers among Ashkenazi Jews can be determined in about 98% of the cases, which makes prenatal diagnosis for Canavan disease in the risk population possible.