Biallelic pathogenic CRB1 variants have been linked to two severe, early-onset forms of retinal dystrophy: they have been found to cause 3–9% of autosomal recessive retinitis pigmentosa (RP) cases and 7–17% of autosomal recessive Leber congenital amaurosis (LCA) [23,24,25]. This evidence concerns the gene CRB1 and Leber congenital amaurosis.