The primary concern is germline editing, those changes that are done in the DNA of human eggs or sperm or early-stage embryos so that every cell in the resulting children—and all of their descendants—will carry the edited trait. There has already been, and rightly so, general acceptance of what is known as somatic editing, the changes that are made in targeted cells of a living patient and do not affect reproductive cells. If something goes wrong in one of these therapies, it can be disastrous for the patient but not for the species.
