ABSTRACT
Canavan disease(CD) is a rare autosomal recessive leukodystrophy caused by the deficiency of aspartoacylase and the accumulation in brain of N-acetylaspartate(NAA). CD has been reported mainly Ashkenazi Jews but also occurs in other ethnic groups. Usually it presents as early as the third month of life with megalencephaly, hypotonia later progressing to hypertonia, psychomotor and mental retardation, blindness, occasionally deafness and seizure. Diagnosis is based on the clinical feature, N-acetylaspartic aciduria, radiologic and pathologic findings. Histologically, the affected white matter shows extensive vacuolation and demyelination. There is no treatment for CD and the only prevention is through genetic counselling and prenatal diagnosis. We experienced a case of Canavan disease that was presented with hypotonia and developmental delay. Diagnosis was confirmed histologically. Radiologic findings are extensive high signal throughout the white matter on T2-weighted MRI and increased NAA peak and decreased choline peak of the white matter on MR spectroscopy.