CRB1 and severe early-childhood-onset retinal dystrophy: Biallelic pathogenic variants in the CRB1 gene are associated with severe retinal dystrophies, including early onset severe retinal dystrophy/Leber congenital amaurosis (EOSRD/LCA), retinitis pigmentosa (RP), cone–rod dystrophy (CORD), and macular dystrophy (MD).