CLN7 Batten disease, also known as variant late infantile neuronal ceroid lipofuscinosis type 7 (vLINCL7), is an ultra-rare form of Batten disease caused by biallelic mutations in MFSD8 (CLN7), which encodes a putative lysosomal transporter of unknown function (10). Here, MFSD8 is linked to juvenile neuronal ceroid lipofuscinosis.