Gattaca is the semi-dystopian vision of our future if we just walk blindly down this path without legislating it properly in advance.

For those who haven't seen the movie: Rich people start paying for perfect "designer babies". A person's genetic information becomes their whole identity; businesses only hire employees with the most genetic predisposition towards being good at the job, while regular people conceived "the old-fashioned way" get McJobs. Even wearing glasses is treated like a crippling disability that immediately and visibly marks someone as "inferior".

It is extremely important that we pass laws to ensure that genetic engineering doesn't create a new caste system.