A neuronal ceroid lipofuscinosis that is characterized by a late infantile onset of symptoms (seizures or motor impairment followed by mental regression, myoclonus, speech impairment, loss of vision, and personality disorders) and a mixed combination of 'granular,' 'curvilinear,' and 'fingerprint' profile lipopigment patterns and has_material_basis_in homozygous or compound heterozygous mutation in the CLN8 gene on chromosome 8p23. [ url:https://www.ncbi.nlm.nih.gov/pubmed/15024724 url:https://www.ncbi.nlm.nih.gov/pubmed/15965709 http://purl.obolibrary.org/obo/ECO_0007645 url:https://www.ncbi.nlm.nih.gov/pubmed/15074367 ]