Below is an instruction from Human. Write a response.
    ### Instruction:
    What is (are) Neuronal ceroid lipofuscinosis ?
    ### Response:
    Neuronal ceroid lipofuscinosis (NCL) refers to a group of conditions that affect the nervous system. Signs and symptoms vary widely between the forms but generally include a combination of dementia, vision loss, and epilepsy. Although the NCLs were historically classified according to their age of onset and clinical features, the most recent classification system is primarily based on their underlying genetic cause.
    