I'm not sure about the exact philosophical mechanics required to transfer rights from the future to the present (or however you want to phrase it) but parents should not be drinking during pregnancy; and it's for their future child's sake that they shouldn't.
Foolishly subjecting your child to an unproven genetic therapy could ruin their future to an extent closer to the mob example than the TV example.
Not editing in this case could be construed as future child abuse or even murder.
As a note, chances of a child given the therapy, if it's randomly working, are no different than general population, most likely.
And if they're better, there goes this argument.
Fearing known unknowns more than unknown unknowns is not logical. Of course people do it all the time.
Why does nature get to play the dice but we cannot?
That's not true - the average gene is more likely to be working than not, and the average mutation is more likely to break something, if it changes anything, than not.