Using a gene augmentation approach, subretinal injection of AAV encoding the full RPE65 gene was found to be both safe and efficacious in several concurrent trials.277,278,279,280 LCA is the leading cause of childhood blindness and is caused by mutations in at least 18 different genes.281 LCA10, the most common form of LCA, is caused by mutations in the approximately 7.5kb CEP290 gene, and is therefore not amenable to the standard gene therapy approach employed for LCA2 due to the large size of the disease-causing gene. The gene discussed is CEP290; the disease is Leber congenital amaurosis.