Amniocentesis was performed in four pregnancies at risk for Canavan disease (CD). In all families both parents were of Ashkenazi-Jewish origin and harboured the C854 mutation in the cDNA of the aspartoacylase gene. Using DNA analysis of the amniotic cells, three fetuses were predicted to be non-affected and one fetus was predicted to be affected. The concentration of N-acetylaspartic acid (NAA) in the amniotic fluid was in agreement with these results. In urine samples of the three newborns predicted to be non-affected, the concentration of NAA was normal. Tissues of the aborted fetus were not available. We conclude that DNA analysis is probably a reliable method for prenatal diagnosis of CD.