Today the United Kingdom’s House of Commons voted to allow a new medical technique that uses DNA from three individuals to create a human baby.
Before you let it creep you out, know that the point is to prevent genetic conditions—specifically mitchondrial diseases—being passed from mother to child. Mitochondria are cells’ energy generators and have their own DNA, passed down exclusively from the mother. When mutations occur in that tiny slice of DNA, the results can be catastrophic.
The procedure authorized in the U.K. replaces the mother’s faulty mitochondrial DNA—and only the mitochondrial DNA—with some from a healthy female egg donor. The child’s nuclear DNA, which is responsible for all the things that we normally associate with DNA, like height and eye color, comes solely from the biological mother and father.
Critics warn that this is the first step in a slippery slope toward genetic engineering of human babies. And indeed, these children will be genetically modified, and their offspring in turn will carry those genetic modifications.
So are we careening inevitably toward a designer baby marketplace where you can adjust your future child’s height as easily as you adjust shoe sizes on Amazon? It seems unlikely at this point. There is still a categorical difference between selecting individual “alleles,” such as eye color, and using third-party mitochondria as a basis for creating a tiny part of another couple’s offspring.
Furthermore, the U.K.’s Public Health Minister Jane Ellison insists that the procedure will be conducted within the context of a “highly respected regulatory regime.” The bill was voted in favor 382 to 128 but still requires a vote in the House of Lords, the United Kingdom’s upper house of Parliament, before becoming law.