The whole issue of whether gene manipulation should be permitted at all or not is a wasted debate. The genie is irretrievably out of the bottle. The only pertinent question is how to use legislation and public policy to regulate genetic engineering so that it is not misused. Genetic engineering will be to this century what atomic energy was to the previous one.
In another few generations, genetically enhanced humans will be increasingly commonplace. On one hand, this will mean fewer defects and inherited diseases, longer life-spans, less illness. On the other, it will mean increasing numbers of persons with enhanced capabilities. Persons who can smell things a quarter-mile away, or hear long distances. Persons who have had specific genes from animals grafted into their predecessors, causing them to inherit abilities like radar sense or seeing in the dark.
Today, Dr. Xavier's X-Men and Magneto's mutants are but a comic book fantasy. In the 22nd or 23rd centuries, they might be political and social controversy. Moreover, as humans move out into the solar system and to other stars, other genetic modifications would become convenient. A breed of people that is not only unharmed by radioactivity, but absorbs and metabolizes it as nourishment. People who can walk easily in much heavier gravity, lift huge weights effortlessly, run as fast as beasts.