Don't sweat it @hej - I suspect the writers just didn't know enough about biology to confidently add any specifics. However, the real danger is that if they had tried, the information would have become outdated - certainly ideas about epigenetics appear to have repeatedly changed, and significantly so, over the past few decades, to the point where it's no longer seen as an addendum to an established field (genetics) but instead an embryonic new science in its own right.
Thanks for the reassurance.
I will give them the benefit of the doubt and just say lazy. A friend of mine is a veteran, and he said scriptwriters' knowledge of the military is pretty bad. Even when they have consultants, they regularly err. My friend told me, he cringes whenever he hears 'well-oiled, military machine.' He knows of no such thing!
For an unusually egregious example, see the imdb page of Crimson Tide. The litany of folly is huge!
Your comment about becoming outdated certainly applies sometimes, but not to the scene in Blade Runner.
Too, you remind me of a statement by George Gamow (astronomer) in one of his books I read. I think he was doubting the existence of either black holes or neutron stars. Either way, he was expressing an opinion that was wrong.
I'm all for discarding the factual when it interferes with good story telling. Yeah, I'm kind of uptight about verisimilitude -- but not all the time. If an author/screenwriter captivates me, I can ignore a lack of reality.
Otherwise, I wouldn't enjoy 99.5% of Blade Runner, you know?