Disease-causing sequence variants in CRB1 have been identified in a broad range of phenotypes, including the early-onset disorders LCA/EOSRD and retinitis pigmentosa with and without a Coats-like vasculopathy, a later-onset macular dystrophy and isolated autosomal recessive foveal retinoschisis.74–77 Approximately 10% of LCA/EOSRD patients harbour variants in CRB1. 9 18 The CRB1 protein is known to colocalise with the zonula adherens, forming a major component of the outer limiting membrane and is believed to have a role in retinal development. This evidence concerns the gene CRB1 and severe early-childhood-onset retinal dystrophy.