And of course we mustn't forget the reaction to He Jiankui, who claims to have created the first permanently modified humans, and the response in China was to jail him and fine him. It's not just the West.
Gene therapy done in a medical setting where society has had a chance to understand what's going on isn't really eugenics, or is a form that isn't "bad". It's different from "sterilize the defectives" and "X people are Yer then Z people", especially because the people doing this have consulted extensively with bioethical experts and have also subjected their plans to scrutiny by the larger society.
Fortunate! That's very fortunate!
> rational eugenics
No such thing unless your basis for it is incomplete or corrupted.
You could say this counts as Eugenics, but maybe people just need a different word since Eugenics is so tainted.
I think if there was a test for Down's syndrome and a gene therapy cure, that would almost certainly be deployed, and advocates for people with Down's aren't going to have a big problem with that. People learned from the autism speaks debacle.