CRB1 and retinal disorder: Genetic variants in Crumbs cell polarity complex component 1 gene [CRB1, Online Mendelian Inheritance in Man (OMIM) No. 604210] cause a heterogenous spectrum of retinopathies; accounting for 7–17% of all Leber congenital amaurosis (OMIM No. 613935, LCA8), 3–9% of autosomal recessive retinitis pigmentosa (RP) (OMIM No. 600105, RP12), autosomal dominant pigmented paravenous chorioretinal atrophy (OMIM No. 172870), and, rarely, a cone‐rod or macular dystrophy [1, 2, 3, 4, 5, 6, 7, 8, 9].