The briefing
Research in Nature reports that delivering the ABE8e-V106W base editor as a protein at fertilization enabled efficient PCSK9 editing in human embryos with development to the blastocyst stage and no detected indels. However, rare chromosomal abnormalities and mosaic off-target or bystander edits were observed, and mRNA delivery caused frequent embryo arrest, underscoring that clinical reproductive use remains premature.
Original headline
Highly efficient base editing at PCSK9 and normal human embryo development