I was thinking about the film Gattica just now, and the scary thing about that movie is
that the "genetic engineering" that the movie proposes is not, as such things in science fiction go, particularly radical. They're not breeding
Julian Bashir-style superpeople, or anything... they're just using gene-mapping technology to pick and choose which kids to be born based on their genetic predisposition for success. This is not unlike where we are headed now, with the identification of this gene that causes such and such and that gene that causes the other disease.
It's scary that the film manages to take something so seemingly positive and turn it around into something horrifying by illustrating a society in which some people can afford it, and some can't.
And yet depending on how you look at it, it's not even a far-fetched cautionary tale, it's simply an allegorical retelling of the imbalance of advantage in our own system, re socioeconomic status and health care and education.
That the protagonist rises above it is still heroic. I'm not sure what that says about the allegory.