Gene-editing human embryos is ethical

The research naturally provoked some bioethical handwringing. “No researcher has the moral warrant to flout the globally widespread policy agreement against altering the human germline,” declared Marcy Darnovsky, the executive director of the Center for Genetics and Society. “The medical risks and social dangers of human germline modification cannot be overstated.” She further urged, “We need to act immediately to strengthen the global policy agreements that put human germline modification off limits.” In The Christian Science Monitor, University of Wisconsin at Madison bioethicist Alta Charo asked, “Do we really want to have the power not just to select among the choices given to us by nature, but to create entirely new choices of our own specification?”

My short answer: Yes.

In what terrible bioethical violations did the Chinese researchers engage? None. The embryos were grown to the eight-cell stage, and none of them could ever have developed into babies. No germline cells with any potential to develop into people were modified. Of the 71 embryos that survived the experiment, 54 were genetically tested. Of these, 28 embryos had the target gene “spliced.” Only four contained all of the replacement genetic material, and even those were mosaics—that is, not every cell had been modified.