First of all, visual impairment is the first presenting symptom in more than 80% of CLN3 patients and compared to early-onset Stargardts disease (STGD1), which is the most common macular degenerative eye disease presenting in the first decade of life (38), the retina in CLN3 disease is affected more extensively and faster, involving both cones and rods, and the optic nerve associated layers (39). Here, CLN3 is linked to CLN3 disease.