Whenever a new fertility procedure is introduced, some medical ethicists and commentators will conjure up a Gattaca-style eugenic future in which all embryos are presorted to look like Uma Thurman and think like Bill Gates. So it goes with a new procedure the Food and Drug Administration is considering this week called mitochondrial manipulation technology, which the New York Times reported on Tuesday under the headline, "Fear of 'Designer Babies' as FDA Weighs Fertility Procedure." The procedure, which thus far has been performed successfully in monkeys, involves replacing defective mitochondria in one woman’s egg with healthy mitochondria from another woman’s eggs. Some are referring to this as “three-person embryo fertilization,” because, as the New York Times writes, it “involves combining the genetic material of three people to make a baby free of certain defects.” Sounds great! But apparently there’s a significant downside. According to the Times, critics fear that the procedure “could lead to the creation of designer babies.”
Opponents of using mitochondrial manipulation in humans, like Marcy Darnovsky, the executive director of the Center for Genetics and Society, argue that any genetic modification of embryos should be verboten. “Otherwise, we risk venturing into human experimentation and high-tech eugenics,” Darnovsky writes in a New York Times op-ed. But Nita A. Farahany, a law professor at Duke University and a member of the Presidential Commission for the Study of Bioethical Issues, says that there is a big difference between replacing defective mitochondria and making sure all babies are blue-eyed and blonde.
“The majority of the concerns”—like Darnovsky’s—“are about opening the flood gates” of genetic manipulation, Farahany told me when we spoke on the phone. They’re not really about this specific procedure, she said. That’s because the majority of the genome, the traits that are passed on from parent to child, are in the nuclear DNA, not the mitochondrial DNA. This particular procedure only involves mitochondrial DNA. Farahany says that there is a bright line that can be drawn around procedures that involve mitochondria, which create the energy that is necessary for cells to divide.
When a woman’s eggs have severe mitochondrial abnormalities, they can have many miscarriages, stillborn children, or extremely sick babies who are unlikely to survive past early childhood. “They will suffer immensely because they can’t get the energy” in order for their brains and hearts to grow, says Farahany. They can have extreme pain and difficulty breathing. Fixing this huge amount of suffering for both mother and child seems like a far cry from creating “designer babies,” and paramount to any hyped-up concern about a slippery slope.
There is, however, a separate set of noneugenic, safety-based concerns about this particular procedure. Some scientists believe that there haven’t been enough animal trials to go ahead with the procedure in humans. Others, like Darnovsky, fear that we don’t know enough about what happens to subsequent generations after the mitochondrial swap is performed. What if trace abnormalities are left behind, and they don’t show up until three generations later?
Still, Farahany believes there is enough data here to proceed to the next step, which would be clinical trials in humans with strong clinical oversight. She points out that other reproductive technologies—like in vitro fertilization, which is now a fairly mainstream procedure—were FDA-approved without knowing what the effect would be on subsequent generations. Farahany also says that in the U.K., the HFEA, a sort of specialized FDA for reproductive technology, has found that there is broad support for mitochondrial replacement. A separate ethical council in the U.K. has found that it is ethical to proceed.
As for what the FDA (which only looks at the science, not the ethics) will decide, it doesn’t look like mitochondrial manipulation technology is going to be approved in the near term. The committee chairman said on Tuesday that many panelists felt “there was probably not enough data in animals ... to move on to human trials without answering a few additional questions.” Farahany says that the FDA is fairly conservative, and she speculated that they wouldn’t want to be the first ones to move forward with a controversial procedure like this. She thinks the Brits will probably go first.
“Every time we get a little closer to genetic tinkering to promote health — that’s exciting and scary,” Dr. Alan Copperman, director of the division of reproductive endocrinology and infertility at Mount Sinai Medical Center in New York, told the New York Times. “People are afraid it will turn into a dystopian brave new world.” But we’re extremely far from a world in which we could—or would want to—manipulate embryos so that they have a variety of “perfect” traits, like our babies were made at the Build-a-Bear workshop. When it comes to this procedure, Farahany has faith that we as a society will build in enough safeguards. “We won’t go to the last step, or even to the next step,” Farahany says. Once the science is in place for mitochondrial replacement, it seems the suffering that it will alleviate far outweighs the risks.