CRISPR/Cas9 โ DNA Repair Follows Cleavage
Why this matters
CRISPR/Cas9 editing relies on the guide to locate the target and the nuclease to create a cut, but it is the cellโs repair machinery that ultimately determines the outcome. Therefore, confirming that the target site was successfully cleaved does not guarantee that the desired genotype has been accurately generated. It is essential to verify not only small indels but also large deletions, rearrangements, mosaicism, and context-specific off-target effects. Differentiate between nuclease-based editing, base editing, prime editing, and ex vivo versus in vivo approaches, while standardizing delivery methods, cell types, and assay conditions. Approved specific therapies do not guarantee the safety of arbitrary edits.
Interpretation boundary
This article explains the concept and the limits of the evidence. It does not provide diagnostic, testing, or treatment decisions for an individual patient.