Technical advisor: Dr Michael Antoniou

More papers have been published on unintended outcomes and risks of gene editing in medical research on human and animal cells and laboratory animals, compared with plants. The results have implications for the gene editing of farm animals. The problems found with human and animal gene editing are increasingly being confirmed in plant gene editing.

The unintended mutational (DNA damaging) outcomes summarized below occur after the gene-editing tool has completed its task of creating a double-strand DNA break. The mutations occur as a consequence of the cell’s DNA repair machinery, over which the genetic engineer has no control. So even if scientists eventually succeed in avoiding off-target mutations, most of the unintended mutations described can still occur at the intended gene-editing site.