Creating babies from the DNA of three people — a man and two women — one day might prevent mothers from passing on devastating genetic diseases, and advisers to the government now say it's ethical to test under certain conditions.
At issue is a kind of DNA that children can inherit only from mom, not dad: genes that are inside the mother's mitochondria, the energy factories in cells. Britain last year became the first country to allow use of a fertility technique to create embryos by swapping a mother's defective mitochondrial DNA with healthy genetic material from a donor egg.
Now the Food and Drug Administration is considering whether to allow that so-called mitochondrial replacement technique to be tested in the U.S. But it's controversial, in part because such alterations could be passed to future generations.
In a report requested by the FDA, the prestigious Institute of Medicine said Wednesday that it is ethical to do such research if initial experiments follow certain strict safety steps. They must target women at high risk of passing on a severe disease — and limit the first pregnancy attempts to male embryos. That's because males can't pass any mitochondrial alteration to their own children.
"Mitochondrial DNA disease can be extremely devastating, and for the women who are at risk of passing it on to their children, they have no other option by which to pursue having a child that's genetically related to them," said Jeffrey Kahn, a bioethicist at Johns Hopkins University who led the Institute of Medicine panel. "It is ethically acceptable to go forward, but go slowly and with great caution."
The FDA ultimately will determine if there has been enough basic research into the safety and potential effectiveness of the approach to allow studies in people. It's not clear when the agency will decide. Also among the questions is whether recently passed budget legislation addressing modification of embryos would bar the FDA from moving forward.
"It's unlikely we'll find any cure once the child is born already with these mutations," said Dr. Shoukhrat Mitalipov of Oregon Health & Sciences University, the field's leading U.S. researcher who is discussing human studies with the FDA and welcomed Wednesday's report. "The best way is to prevent it."