CLN3 and juvenile neuronal ceroid lipofuscinosis: To date, 38 CLN3 variants, which are associated with JNCL or isolated retinal dystrophy, have been reported (Chen et al., 2019; Kousi, Lehesjoki, & Mole, 2012; Ku et al., 2017; Lerner et al., 1995; Munroe et al., 1997; Sarpong et al., 2009; Wang et al., 2014; Wisniewski et al., 1998).