CGS-authored

Ethical and social concerns about modifying DNA include whether parents have a right to tweak the genetic makeup of their future children and whether only the wealthy will be able to afford such tweaks. Some argue that modifying eggs and sperm should never be done because it’s impossible to obtain the consent of the unborn and any offspring in later generations.

“Scientists may be being carried away by their own enthusiasm for what they’ve developed,” says Marcy Darnovsky, executive director of the Center for Genetics and Society, a nonprofit that is working to ban the editing of human eggs and sperm.

Two groups of scientists issued public warnings this year about the dangers of genetically modifying humanity’s family tree, among them the potential for unforeseen problems. One called for more public discussion and the other proposed a voluntary moratorium on editing human reproductive cells.

Both groups focused on nuclear DNA — the kind that we inherit from both of our parents and that determines hair color, eye color and other characteristics. Scientists tend to put mitochondrial DNA, which is inherited...