“This seems like a path toward having no people with Down syndrome, having no people with certain disabilities, even though there are people that have those disabilities that live fulfilling lives,” he said. “You’re talking about culling a tree of human evolution, right?”

I've heard this argument before and I find it insulting, as though it's somehow a moral wrongdoing to prefer children without birth defects. If I could spare my future children from MS, schizophrenia, Downs, Huntington's, Alzheimer's, etc., I'd do it in a heartbeat. Framed differently, who would deliberately inflict a healthy newborn with any of those congenital disorders? That they might live a fulfilling life in spite of their disorder wouldn't make it any less cruel.