[zmmmmm]

Apart from the other points people have made, it's worth noting that these days parents can avoid having children with inherited genetic disorders through IVF. While there will always be a component of spontaneous mutations resulting in genetic disease, we may approach within a couple of generations a state where most inherited disorders actually disappear or reduce to vastly lower prevalence over time.

[nicolas_t]

Some backward countries (like my own France) forbid that due to concern over eugenics.