Why you should care
Because the limits of our ethical comfort zone are sometimes where the learning happens.
After years of watching her son be confined to a hospital bed, Cindy Salt lost him at the age of 25 to mitochondrial disease — a rare but terrible condition that causes painful symptoms and almost always results in death. Salt and her 31-year-old daughter also show symptoms of the disease, including severe migraines and fainting spells. In fact, her daughter has chosen to adopt two children out of fear she might pass on her mitochondrial disease. Alas, Salt notes, “it’s sad that our gene pool stops here.”
But it might not have to anymore for those in this Cincinnati family’s position. Turns out that mixing three people’s DNA can help prevent children from being born with mitochondrial disease. Sound sci-fi? Well, children in this scenario — like Alana Saarinen, a happy and healthy teen with three genetic parents — are real, and we can expect more of them. Her mother, Sharon, was one of the first women to try an experimental in vitro fertilization procedure called mitochondrial DNA transfer.
I totally understand how people may think it is wrong to do this, but they have not had to watch their children suffer.
Cindy Salt, who lost her son to mitochondrial disease
Never heard of it? Well, it may just go mainstream someday now that the U.K. has become the first country to legalize the technique. That decision could lead to its approval in other countries like Australia and the U.S. The procedure itself consists of mixing a mother’s genetic material (her egg nucleus) with a donor’s mitochondria, which is what provides energy for cells to divide and grow. Replacing the mother’s abnormal mitochondria with that of a healthy donor allows the child to grow without passing the faulty gene on to future generations. And besides its immediate application, the procedure opens the door to a new field of genetics and, potentially, parenthood.
Of course, the mention of “three-parent babies” is setting off alarm bells for those who think breaking the restriction on genetically engineered, inherited genes will be a slippery slope to “designer babies.” Bioethicists also question our right to pass modified genes down to future generations, and some worry about unpredictable long-term consequences. “There is a concern that more animal work needs to be done,” says Arthur Caplan, director of medical ethics at NYU School of Medicine.
But for families suffering from mitochondrial disease, this seemingly strange, futuristic procedure is a ray of hope. “I totally understand how people may think it is wrong to do this, but they have not had to watch their children suffer,” says Salt. Despite the term three-parent, most of the embryo’s DNA still comes from two parents since the mom’s nucleus remains intact. That’s what determines, say, someone’s hair color or personality traits. And legal experts in both the U.K. and Canada say there shouldn’t be any custodial battles either — in the U.K., at least — because women who contribute the mitochondria are not legally a parent and are not even allowed to be identified.
As for its medical applications, mitochondrial disease could just be the tip of the iceberg. While it’s too early to say if this technique can prevent other disorders, it does open a new field of potentially lifesaving research because mitochondrial malfunction has been linked to everything from Alzheimer’s to cancer to heart disease. Susan L. Solomon, chief executive officer of The New York Stem Cell Foundation, where the technique was also developed, hopes the organization will be able to expand the research. “The U.S. needs to take advantage of the careful consideration the U.K. has already given to the matter and offer our citizens the option of choosing how best to have happy, healthy families,” she says.
For now, mixing DNA is only intended for medical purposes, but the ability to create genetic links between a child and three parents does open the door to one day bringing biological parenthood to groups like lesbians or polyamorous trios. Consider it a modern twist on Three Men and a Baby. “Once it has been established with the therapeutic goal then other rationales can be considered,” says Caplan. Science is still decades away from finding a viable technique, but legally, three-parent children already exist in many countries like Canada and Argentina, often the fruit of same-sex couples who want the sperm donor to also be a parent.
So, what next? After a hearing on the issue last year, the U.S. Food and Drug Administration is currently deliberating whether to green light human trials. There’s still a long road ahead before three-parent babies become as common as their “test tube” counterparts, though some think there’s no stopping the ball once it starts rolling. “Now that the U.K. has made the step, it won’t be long until the question comes here [to France],” says Laurent Janny, a French gynecologist. “And when it does, I don’t see how we could refuse it.”