Our investigations demonstrate that the ASPA gene is transcribed in the lymphocytes to a similar extent if compared with fibroblasts. Based on the protein content, aspartoacylase activity is lower in EBV-transformed lymphocytes than in fibroblasts (< 20%), but even transformed lymphocytes revealed a difference in activities between patient cells and negative controls. This opens a new diagnostic perspective, and may also help with the systematic study and characterization of patients with CD which is currently conducted by our metabolic center. More comprehensive information on CD is a prerequisite for better counseling on the clinical outcome. Background: Canavan Disease(CD) caused by deficiency of aspartoacylase and increased excretion of N acetyl aspartate (NAA)is common in Ashkenazi Jews and has also been reported in other populations.Mutations causing Y231X (exon5) and E285A (exon6) are prevalent amongst Jews while A305E (exon6) accounts for 60% of non Jewish patients. Indian data is scarce which may have been due to non availability of NAA analysis by GCMS till recent past.Study design:We report a study of 35 clinically suspected CD cases (mean age 27 months) referred from across the country for NAA analysis. Clinically they presented with macrocephaly, developmental delay, poor head control and hypotonia. Results: A 20-200 fold increase in NAAwas obtained in around 8 patients (23% of total) of which only 50% were born to consanguineous couples suggesting prevalence of CD amongst several communities in India. As an initial molecular work up we screened 6 CD patients for prevalent mutations Y231X, E285A and A305E by sequencing exons 5 and 6. These mutations were not detected in our patients, suggesting a varied set of mutations amongst them.