Canavan disease is a leukodystrophy caused by ASPA mutations that diminish oligodendroglial aspartoacylase activity, and is characterized by markedly elevated brain concentrations of the aspartoacylase substrate N‐acetyl‐l‐aspartate (NAA) and by astroglial and intramyelinic vacuolation. Here, ASPA is linked to Canavan disease.