Monarch Disease Ontology identifier MONDO_0008769 (neuronal ceroid lipofuscinosis 2) is a condition associated with mutation(s) in the TPP1 gene, encoding tripeptidyl-peptidase- 1. The condition is one of a group of genetically heterogeneous neurodegenerative disorders, characterized by accumulation of intracellular lipopigments. Also known as: CLN2, TPP1 neuronal ceroid lipofuscinosis, ceroid lipofuscinosis, neuronal, type 2, neuronal ceroid lipofuscinosis 2 variable age at onset, neuronal ceroid lipofuscinosis caused by mutation in TPP1, neuronal ceroid lipofuscinosis type 2.