PPT1 and juvenile neuronal ceroid lipofuscinosis: The most common childhood forms of Batten disease result from mutations in either CLN1 (Classic Infantile Neuronal Ceroid Lipofuscinosis; cINCL; Haltia–Santavuori), CLN2 (Classic Late-Infantile Neuronal Ceroid Lipofuscinosis; cLINCL; Janský–Bielschowsky) or CLN3 (Classic Juvenile Neuronal Ceroid Lipofuscinosis; cJNCL; Spielmeyer–Sjögren).