The impact that germ-line gene therapy will have on society is controversial. Germ-line cells are reproductive cells— sperm or eggs. Germ-line gene therapy, also known as human inheritable genetic modification (IGM), involves the insertion of healthy genes into these germ cells to create a beneficial genetic change—such as eliminating a genetic disease—before a child is born. Some believe society will benefit from germ-line gene therapy because debilitating and life-threatening genetic diseases could be eradicated by such therapies. Others fear that the technology will be abused, and humanity will become divided between the genetic haves and the genetic have-nots.

Although scientists have not yet perfected germ-line gene therapy nor performed sanctioned experiments on human subjects, some commentators envision a terrifying future. Journalist Sally Deneen paints a frightening picture:

It will start innocently enough: Birth defects that are...