Analysis of CRB1 Pathogenic Variants Correctable with CRISPR Base and Prime Editing

The mouse and human retina contain three major Crumbs homologue-1 (CRB1) isoforms. CRB1-A and CRB1-B have cell-type-specific expression patterns making the choice of gene augmentation strategy unclear. Gene editing may be a viable alternative for the amelioration of CRB1-associated retinal degenerations. To assess the prevalence and spectrum of CRB1-associated pathogenic variants amenable to base and prime editing, we carried out an analysis of the Leiden Open Variation Database. Editable variants accounted for 54.5% for base editing and 99.8% for prime editing of all CRB1 pathogenic variants in the Leiden Open Variation Database. The 10 most common editable pathogenic variants for CRB1 accounted for 34.95% of all pathogenic variants, with the c.2843G>A, p.(Cys948Tyr) being the most common editable CRB1 variant. These findings outline the next step toward developing base and prime editing therapeutics as an alternative to gene augmentation for the amelioration of CRB1-associated retinal degenerations.