One major problem is delivering the genetic material into the cells. Early trials used viruses to slip the new DNA past the body's immune system. Problems arose because in many cases the virus would transfer material in random, even harmful ways. Alternate methods aim at harnessing the body's own genetic repair processes to spot defects in the DNA, remove them and stitch in replacements. Then there are children.
Parents can already select a kid's sex and screen for genetic illness.
From there it's a short step to selecting for things like intelligence, beauty and athleticism, which begins to raise disturbing ethical questions. Though still in its infancy, gene therapy offers tantalizing possibilities. It has the potential to revolutionize medicine as we know it, adding new meaning to personalized health care. Time Inc. New Media. All Rights Reserved.