Three Parents

As I catch up on reading The Economist and Time, I find a couple articles on Britain's recent approval of the creation of children with genetic material from three people. It's a little complicated, but an embryo's DNA has several components: the egg, the sperm, and the mitochondria (often forgotten). The mitochondria are inherited from the mother. Up until now, it's been mostly theoretical, but the concept is that the nucleus of an egg with damaged mitochondrial DNA can be transferred to the body of an egg with normal mitochondria, and subsequently fertilized. The resulting embryo would have DNA from three separate people (two women and a man) though whether they are all "parents" is a separate issue (in my mind). Although mitochondrial diseases are quite rare, they are often untreatable, and this creates a process for women with mitochondrial diseases to have children without risking passing their disease on. I don't think it'll be used very often, but the idea is fascinating, and at this time, Britain is the only place that recognizes it.

This will be controversial, I know. However, I don't think it's any different than screening embryos for an incurable or fatal disease. In this case, we are simply excluding mitochondrial DNA that is diseased. While doing so requires mitochondrial DNA from a third person, I don't think its "weirdness" or "unnatural nature" is a reason to ban it. Many procedures we do in medicine used to be "weird" or "unnatural" - from blood transfusions to organ transplantation to artificial hearts. That's not a good argument for prohibiting a medical procedure. Instead, we must look at its risks and benefits, and while most of the risks are unknown at this time, its benefits - allowing women with mitochondrial diseases to have children without passing on those diseases - are laudable.

Image of mitochondria and DNA is shown under Creative Commons Attribution Share-Alike License, from Wikipedia.