The other side of the Rubicon
Embryo study’s success is shifting the topic from ethics to efficacy
In the end, it might be the efficacy that guides the ethics. By showing that editing of human embryos using CRISPR can be performed efficiently and without leading to the much-feared slew of off-target cuts, a team at Oregon Health & Science University has changed the conversation around germline gene editing from whether it should ever be allowed to where to start and how to do it safely.
What’s clear is that by conducting a well-designed and highly regarded study, the researchers have moved the field beyond a point of no return, and a wave of new experiments across the scientific community is likely to follow.
What set it apart from the three previous reports of editing in human embryos, which were all performed in China, were the high success rate and low mistake rate.
Two of the earlier studies were performed in non-viable embryos that couldn’t result in live births; the third involved a small number of healthy, viable embryos. Each paper showed some level of gene correction in the embryos, but produced only a small percentage of incompletely corrected, or mosaic, embryos. Those studies precipitated an outcry of ethical concerns that scientists would surge ahead before demonstrating the method could produce sufficiently