Therefore, according to the presenting phenotype, patients were originally clustered into the six different NCL subtypes [4], consisting of congenital (CLN10), infantile (CLN1), late infantile (CLN2), variant late infantile (CLN5, CLN6, CLN7 and CLN8), juvenile (CLN3) and adult (CLN4) NCL. Here, TPP1 is linked to neuronal ceroid lipofuscinosis.