For some reason, there’s a lot more objection to genetically modified grain than there is to genetically modified people:
The same techniques that could conceivably end all genetically-occasioned birth defects could also be used to produce monsters.
Who would do such a thing, and why? Men of little skill or understanding, unaware of the consequences of their undertakings. Cruel men, who like to watch others suffer. Men with skill but without moral or ethical standards, who would produce distorted caricatures of humans for wealthy others ready, willing, and able to pay them. There may be other possibilities, but those are sufficient for now.
The base stock for such horrors would be readily available: zygotes “left over” from in vitro fertilization efforts. Many would-be parents are unaware of what happens to such “leftovers.” Others are unconcerned about their fates; they’ve got their babies, so nothing else matters.
Just about as soon as it can be done, it will be done — and no law or exercise of State power will prevent it.
I’m thinking it’s worse than that. The State’s power of the purse — your purse and mine, that is — will end up subsidizing the worst of them, on the basis that it’s unfair, unjust, and several other “un” words, to discriminate in favor of the best of them.