Gattaca is set in the not too distant future, a future where science rules and mistakes just don"t happen. The new wave in this future is to have babies that are streamlined to have the best of both parents. All of the "abnormalities" of the genetic process are eliminated.
Only seconds after a baby is born, the doctors are able to work out your date of death, how you died, and the probability of any conditions that may arise during your lifetime.
Not every parent takes this option, they still conceive the old fashion way, which are now called "faith births", putting your child's fate in the hands of god, this kind of practice is frowned upon though. This is where Vincent comes in. He was a faith baby with a 99% chance of not living past thirty years of age because he had it in is his genes that he would have a heart condition. He wanted nothing more than to be an astronaut, but "Gattaca" (kind of like NASA) only takes the cream of societies crop and people like Vincent aren"t that. So he decides to become someone else - Jerome Morrow. The real Jerome is a paraplegic but according to all records he's still a walking talking perfectly functioning member of society. So Vincent becomes Jerome, changes his looks, height body structure and turns his life upside down to live his dreams.
No, I don"t agree with how Vincent is treated in this story. Just because he hasn"t got the greatest genetic profile, or because he wasn"t a man made baby, society treats him as if he is handicapped in some way, which is totally wrong. .
He is a perfectly functioning human being and has the brainpower and dreams to match most, but because of his genes he is never allowed to reach his full potential, the best schools are for those with the best profiles, Degenerates like Vincent simply aren"t allowed.
Once he became Jerome, everyone treated him like he should have been all along, the upper echelon of society treat each other with respect but not those with an inferior genetic profile.