Neuronal Ceroid-Lipofuscinosis (NCL) is an inherited disorder that affects neural systems. Individuals with this disorder may have gradual loss of previously acquired skills or fail to learn to walk or speak at all. They can also have mild to severe intellectual disability, behavioral problems, vision impairment, seizure and early death. Symptoms can appear starting in infancy, childhood, or later on in adulthood. Individuals with earlier onset often require the use of a wheelchair by late childhood and typically do not survive past their teens. Currently, there is no cure for NCL, but medical surveillance and care may help to improve some symptoms and overall condition of life. Individuals with NCL have been characterized traditionally according to the age of onset and order of appearance of clinical features into infantile, late-infantile, juvenile and adult types. Pathogenic variants in more than 10 genes can cause NCL, and the most common genes include TPP1, PPT1, CLN3, CLN5, CLN6 and CLN8. Pathogenic variants in the PPT1 gene are the major cause of infantile NCL and may cause other types of NCL as well.