Complex sentence: The latter is sometimes seen as more ethical because the changes are made with informed consent; a counterargument is that no harm is done to a person born with modified genes because the person had no control over their genetics in the first place.
Split into simpler sentences: The latter is sometimes seen as more ethical because the changes would be made with informed consent. A counterargument is that no harm is done to a person born with modified genes because the person had no control over their genetics in the first place.