The Human Genome Project will produce information permitting increasing opportunities to prevent genetically transmitted harms, most of which will be compatible with a life worth living, through avoiding conception or terminating a pregnancy. Failure to prevent these harms when it is possible for parents to do so without substantial burdens or costs to themselves or others are what J call “wrongful handicaps”. Derek Parfit has developed a systematic difficulty for any such cases being wrongs — when the harm could be (...) prevented only by preventing the existence of the individual who would have a worthwhile life even with the handicap, then bringing him into existence with the handicap does not make him worse off and so does not wrong him. I argue that a non “person‐affecting” principle requiring the avoidance of suffering and limited opportunity correctly accounts for cases of wrongful handicaps without requiring that the individuals with the handicap have been made worse off and therefore wronged. It is an advantage, not a difficulty, of this account that it does not imply that the person with the handicap has been wronged or is a victim with a special moral complaint. (shrink)