The biggest problem I had with Gattaca is the *main* part, not being able to get into the space program because your genes are bad, is not Sci Fi. It's been part of NASA since it started. The fact that the main character would risk a multi-billion dollar program was just selfish and irresponsible.
As another example the Air Force also screens. They might not use direct genetic testing but many of the tests to be a fighter pilot amount the same thing. Example: Eye sight not 100% perfect, no piloting for you.