Genotoxicity concerns for base and prime editors in hematopoietic stem cells

Although base and prime editors can be highly efficient in human hematopoietic stem cells, we find they can cause adverse cellular responses, including reduced engraftment and the generation of DNA double-strand breaks and genotoxic byproducts, albeit at a lower frequency than Cas9. We also find that base editors increase the genome-wide mutagenic load.