CLN3 and juvenile neuronal ceroid lipofuscinosis: Juvenile-onset neuronal ceroid lipofuscinosis (JNCL) or Batten disease, a severe neurodegenerative lysosomal storage disease of childhood characterized by accumulation of lipofuscin-like material, is caused by mutations in CLN3. JNCL presents between the ages of 6–10 years with visual failure, followed by epilepsy and progressive cognitive and motor deterioration, leading to premature death.