The neuronal ceroid lipofuscinoses (NCLs) are the most common group of inherited, progressive neurodegenerative diseases of childhood. They are characterized by a combination of visual impairment, cerebellar ataxia, and signs and symptoms of diffuse telencephalic involvement, such as seizures, behavioral disturbances, and cognitive deterioration. Juvenile neuronal ceroid lipofuscinoses (JNCLs), also known as Batten disease, is an autosomal recessive heterogeneous group of neuronal ceroid lipofuscinoses, typically characterized by onset at early school age between the ages of four and 10 years with vision loss due to retinopathy, mental and motor deterioration, seizures, and early death.