ABCA4 is one of the most common disease-causing genes in inherited retinal degeneration (IRD) [4], with a prevalence of approximately 1 in 10,000 people, and is considered the main cause of Stargardt disease 1 (STGD1; OMIM 248200) [5,6]. This evidence concerns the gene ABCA4 and severe early-childhood-onset retinal dystrophy.