In this book the authors explain what our personal DNA code is, how a few differences in its long list of our DNA letters makes each of us unique, and how that code influences our appearance, our behavior, and our risk for such common diseases as diabetes or cancer. News stories report almost daily that scientists have linked a certain gene to a disease like Alzheimer's or macular degeneration, or to a condition like depression or autism, or to a trait like aggressiveness or anxiety. Accompanying this progress in unraveling the genetic basis of disease and behavior are new technologies that are rapidly reducing the cost of reading someone's personal DNA (all six billion letters of it). Within the next ten years, hospitals may present parents with their newborn's complete DNA code along with her footprints and APGAR score. Here the authors, both geneticists help us make sense of the genetic revolution that is upon us. They tell real life stories that hinge on the inheritance of one tiny change rather than another in an individual's DNA: a mother wrongly accused of poisoning her young son when the true killer was a genetic disorder; the mountain-climbing brothers with a one-in-two chance of succumbing to Huntington's disease; the screen siren who could no longer remember her lines because of Alzheimer's disease; and the president who was treated with rat poison to prevent another heart