There's an old scifi novel called Beggars In Spain that deals with this. The author is fairly obscure, and the book is out of print. I was told that in the novel, billionaires pay to create perfect kids. The resulting adults have every advantage and take over the planet, causing a backlash that results in a revolution and the dispossession of the perfect people. Like Cain, they are forced to wander the world forever. They are easily identified, so people know not to feed or comfort them.
I suspect that something similar would happen should we create perfect people, or even people with Heroes-like superpowers. Superpowered people would have an extra problem in that they might be powerful enough to destroy earth or even the spacetime continuum, and could institute a dictatorship under threat of absolute destruction.
The other side is the forced elimination of undesirables, either Nazi style or via abortion/infanticide. The Nazis came frighteningly close to eliminating not only Jews but Gypsies, the latter of who had so many killed that they now only exist in the US. The Germans were reportedly a single won battle away from sweeping into Palestine and eliminating the half million Jews it held. Had that happened, there likely would not be an Israeli state, or it would be in Alaska or Africa or someplace different. Humanity has the power if it so wishes to eliminate ALL undesirables.
The FLDS, the Fundamentalist Church of Jesus Christ of Latter-day Saints, a Mormon splinter group once in Arizona but now mainly in Texas, tried to create a perfect race via inbreeding and parental selection, and the result was massive numbers of genetically deformed babies and the near collapse of their society. Now imagine that on a planetary scale. The survival of humanity would be under serious threat. But people seem bent on it. It appears we'll have to learn the hard way, by extinguishing ourselves.