In murine primary neurons and brain tissue, PPT1 is localized in synaptosomes and synaptic vesicles but not in lysosomes, and, as such, abnormal synaptic functioning could play a role in the CLN1 form of neuronal ceroid lipofuscinosis (Lehtovirta 2001). This evidence concerns the gene PPT1 and infantile neuronal ceroid lipofuscinosis.