Definition:

Jansky-Bielschowsky disease, a classical late infantile neuronal ceroid lipofuscinosis (LINCL), is an autosomal recessive neurodegenerative disease with onset of symptoms between 2 and 4 years of age. Clinical symptoms include seizures, progressive encephalopathy, visual failure, and motor abnormalities. Mutations in the TPP1 gene, that encodes the lysosomal enzyme tripeptidyl-peptidase 1, cause this disease.