Editing the human genome: where ART and science intersect

Avner Hershlag, Sara L. Bristow

The rapid development of gene-editing technologies has led to an exponential rise in both basic and translational research initiatives studying molecular processes and investigating possible clinical applications. Early experiments using genome editing to study human embryo development have contradicted findings in studies on model organisms. Additionally, a series of four experiments over the past 2 years set out to investigate the possibilities of introducing genetic modifications to human embryos, each with varying levels of success. Here, we discuss the key findings of these studies, including the efficiency, the safety, the potential untoward effects, major flaws of the studies, and emerging alternative genome editing methods that may allow overcoming the hurdles encountered so far. Given these results, we also raise several questions about the clinical utilization of germline gene editing: For which indications is gene editing appropriate? How do gene-editing technologies compare with genetic testing methods currently used for screening embryos? What are the ethical considerations we should be concerned about? While further research is underway, and our understanding of how to implement this technology continues to evolve, it is critical to contemplate if and how it should be translated from the bench to clinical practice.