My original comments were almost ten years ago, so I want to elaborate; Stan Lee claimed he was tired of creating new hero origin stories, so mysterious genetic related superpowers controlled by the mind that marked the rise of the Homo Superior was his solution to running out of radiation types.
And it was definitely a trope of science fiction at the time. Star Trek's second episode was about a human mutant developing ESP powers. The British made an serial called The Tomorrow People, which was again, teenagers developing superpowers as a metaphor for adolescence. All that can be traced back to evolution, if the process Darwin described is ongoing, then another race of mankind will emerge and replace H. Sapiens the same way we replaced H. Herrgerman.
So, the idea of mutants per se is probably public domain, (I would be careful how you use the term around Disney, to be sure), the question is, what do you do with it? For Gwen, you created a girl who can't touch anyone without hurting them, which is a really top shelf idea, like grade A metaphor. Gwen has to learn to trust people in order to touch them.
As far as the larger mythos, eh. The series has always dodged the question of how much demon genetics exists in humans. Tara is supposed to be demon free. We've only seen half demons, never quarter or eighth, so we don't know how human the Children of a half listner and human would turn out, aside from ugly. So,, while I agree it's a clever and original induction, not enough evidence.