Yes.
I have fairly serious allergies to most furry mammals, plus when younger I had asthma severe enough to require regular hospitalizations and eczema in some bad spots and some really bad spots.
I would not want my child to have to suffer from the same conditions, no matter that they’re easily treatable.
Seconded on definition request. Suppose there’s a gene for necrophelia, or liking little kids? Or homosexuality? I’m not saying they’re the same at all, except for the fact that all of them would produce a social handicap of some sort. Ensuring your child has a “normal” orientation would be considered a good act by some, getting rid of a “defect”.
Something physical like diabetes or a clubfoot, yes. Something that inhibits intelligence, sure.
Absolutely, in the case of eliminating anything corresponding to disability or shortened life or increased liklihood of having a disease.
Also yes in the case of promoting intellegence or phisical strength or sense of humor or other things that seem undebatably positive. Of course, there is a debate about where to draw the line between undebatable and debatable.
I don’t think I’d tamper with gender or hair or eye color or tall versus short or gay versus straight or lefthandedness. They seem to be in a category of things that have been favored or disfavored without good reason, or for reasons we would actually have been happier not to consider.
Similarly, I’d be tempted to trade away sports prowess to get math skills, and make similar trades, but have to wonder whether it’s wise to give in to those wishes.
A good principle might be to try to imagine, before avoiding some trait, what response I’d hear from somebody who already has it. And, to err on the side of noninterference.