I don't think fast turning is genetic. Perhaps at the very highest end of ability (7-8 tps) there is an element, but to be able to turn at 5 or so tps really does just require solid practice.
I don't mean practice by 'do 200 solves', btw. I mean practice as in 'analyse your turning style, compare it to other solvers, attempt to emulate them, repeat algorithms with different turning styles etc'.
EDIT:
Right, I just watched myself do a T perm and looked at each individual element of each turn, as in, which fingers I used for each one, how much my wrist moved etc, and none of each constituent part was moving particularly quickly at all. As far as I can see turning fast is just a combination of finger flicks that anybody can do and standard speed wrist rotation, done with precision and good timing.