What would I major in for this career?

I just read an article on designer babies being allowed in the US and that sounds pretty cool. I know part of the career would fall under genetics but what would be a more exact major?

Bioengineering.

Genetics. If you truly want to go into that field, you will likely need a Ph.D., an M.D., or an M.D./Ph.D.

I would expect you would have to be a physician.