We have found that transgenic mice expressing the mutations in DNAJC5 found in patients (L115R and L116Δ) develop neuronal lipofuscinosis with the pathological hallmarks observed in patients with Kufs disease/CLN4 and that this lipofuscinosis is not due to the lack of CSPα/DNAJC5. Here, DNAJC5 is linked to adult neuronal ceroid lipofuscinosis.