CLN1 disease (OMIM #256730) refers to a NCL form associated with a childhood onset phenotype (Santavuori et al., 1974; Vesa et al., 1995; Simonati et al., 2009), and a rare adult onset one (van Diggelen et al., 2001). This evidence concerns the gene PPT1 and neuronal ceroid lipofuscinosis.