As NPR reported this morning, researchers in England may soon use genetic therapy to treat diseases that result from defects in mitochondrial DNA.
Mitochondria create energy for cells, and they have their own genes, distinct from the genes that help determine our looks, behavior, and other traits. Because mitochondrial activity is critical to normal cell functioning, abnormalities in mitochondrial DNA can be devastating. Some babies die in a matter of hours.
But because the therapy involves genetic manipulation, it is controversial. While critics are right to insist that we proceed carefully with genetic therapy, many of their arguments are misguided.
For example, they worry that children will be born with the genes of more than two people—while the mother and father will provide most of the child’s genes, another woman will provide the child’s mitochondrial DNA. But we’re all the result of genetic combinations from more than two people. Our genes came from two parents, whose genes came from four grandparents, whose genes came from eight great-grandparents, and so on.
Critics also worry that genetic therapies will be used not only to cure disease but also for eugenic enhancement. Undoubtedly, scientific advances can be misused. Electricity, for example, can be used to electrocute people. But there are better ways to protect against abuse than to deny families the ability to avoid lethal diseases.
Another concern lies in the fact that because changes in mitochondrial DNA will be passed to subsequent generations, any unforeseen harms from the therapy will have effects beyond the child whose embryo was manipulated. This is a reasons to be cautious and very careful, but not a reason to condemn the treatment entirely. All medical treatments can have unexpected and widespread effects, as we have seen with a number of drugs and devices. We should demand rigorous testing and careful monitoring, but we should not block potentially important advances in medicine.
To a considerable extent, it appears that people worry about tampering with nature. In its report, NPR quoted critic David King, who observed that people are troubled by the proposed therapy because “It speaks to something very deep and emotional in the human psyche about how human reproduction is supposed to work.” But of course, drugs, surgeries, and other medical therapies also tamper with nature.
People are correct when they worry about the risks of new biotechnologies. We do need to ensure that potential genetic modifications really will be helpful rather than harmful. But we also should not let our fears of the unknown prevent us from realizing the important benefits of scientific progress.