Precise genetic editing of liver cells in living organisms without unwanted changes in RNA or DNA

The intravenous delivery of cytidine base editors achieved ~21% on-target editing in the liver of mice with phenylketonuria without off-target mutations.

• Cytidine base editors are capable of precise single-base modifications in genomic DNA.
• Off-target activity poses a significant concern for the therapeutic use of base editors.
• In this study, no off-target edits were detected in the RNA or DNA of liver cells.
• The editing process led to the repair of the mutation responsible for phenylketonuria.
• Transitory expression of base editor components resulted in a reversal of the disease phenotype.

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