Star Trek was a meritocratic socialist economy with a World Government, of which we really only see the military/starfleet aspect of everything. There was a hierarchy of jobs based on performance, and there was never any mention of genetic discrimination as far as I know.
This would lead to the banning of genetic engineering on Earth by the mid-22nd century, even research which could be used to cure critical illnesses. This ban was implemented because of the general fear of creating more tyrants such as Khan. It was also felt that parents would feel compelled to have their children genetically engineered, especially if "enhanced" individuals are allowed to compete in normal society.
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By the 24th century, the United Federation of Planets allowed limited use of genetic engineering to correct existing genetically-related medical conditions. Persons known to be genetically enhanced, however, were not allowed to serve in Starfleet, and were especially banned from practicing medicine.
