CRISPR Base Editing and Prime Editing

Base editing changes a single DNA letter without cutting the double helix, which researchers say meaningfully reduces off-target effects compared to standard CRISPR cutting. Prime editing functions like find-and-replace for the genome, able to make more precise edits than base editing alone. The FDA approved Casgevy (exagamglogene autotemcel), the first CRISPR-based gene-editing therapy, for sickle cell disease in December 2023 — a landmark regulatory moment for the field, though Casgevy itself uses the older cut-based CRISPR approach rather than base or prime editing.