Abstract

Genome editing, through its uses in basic research, biotechnology and gene therapy, is poised to transform the world and biology itself. In particular, its application to humans raises concerns of both ethical and technical nature. Is it desirable to edit human embryos to prevent genetic diseases or to increase resistance to pathogens? Will such interventions be reversible and safe? My research shows that when it comes to safety, the darkest place may be under the lighthouse. The frequency and extent of the unintended genetic outcomes of editing at the target site have been underappreciated. These results force a re-evaluation of currently conducted and planned clinical trials.