Britain Moving Too Fast on 3-Parent Children

A procedure newly approved in Britain allows babies to be conceived with DNA from three parents — a mix of DNA that would determine the child's characteristics and become part of the gene pool in future generations. Last year, a U.S. Food and Drug Administration advisory panel wisely decided that this procedure, designed to overcome the devastating effects of mitochondrial disease, wasn't ready for human trials, much less therapeutic use. With its premature approval, Britain has opened the way for three-parent children around the world, because anyone with enough money can travel there for the procedure.

Mitochondria are the specialized compartments within cells that are responsible for creating most of the energy needed by the body. But when a mother's mitochondria are faulty, the resulting disorder can be disabling or fatal to her offspring. Children born with mitochondrial disorder might lose muscle control, suffer muscle weakness and pain, have difficulty breathing and be beset by heart and liver problems.

Researchers hope to overcome this by removing the nucleus from the egg of a woman who has the disorder...