So What if a Baby Has Three Biological Parents?

Arthur L. Caplan, PhD


April 06, 2015

This feature requires the newest version of Flash. You can download it here.

Hello. I am Art Caplan, at the New York University Langone Medical Center, Division of Medical Ethics, in New York City.

You have probably heard the news that the British government approved the use of mitochondrial transplants for people with mitochondrial disease. This decision has raised lot of controversy and is an issue that will be coming to the United States.

Until now, the US Food and Drug Administration (FDA) has not approved mitochondrial transplants, but the FDA is rethinking this position. And with the British saying they will permit this, we need to begin to consider whether we want to move toward allowing this form of genetic engineering.

Some Background

What is mitochondrial transplantation? Basically, the mitochondria are little battery packs. They are in the cell protoplasm, not in the nucleus. But without them, cells do not have sufficient energy to divide. Obviously, that is horrific in terms of organ failure or death in a person who is afflicted with a mitochondrial disease.

Mitochondrial diseases are rare, occurring in perhaps 1 in 4000 children. However, they are rare because many stillborn births and spontaneous abortions are probably related to the failure of mitochondria.

One strategy to fix the problem is to find someone who has had children and knows that she has normal mitochondria, and transplant mitochondria from her egg to those of a woman who has lost a child and knows that she has trouble with her eggs in terms of mitochondrial disease.

It is like a mini transplant—a tiny kidney transplant or a tiny liver transplant performed at a microscopic level. You move the mitochondria from the healthy donor egg and use it to replace the diseased mitochondria in the egg of a woman who wants to try again to have another child. It sounds like a pretty reasonable thing to do. Why wouldn't we do it?

How Sound Are the Concerns?

Is the Procedure Safe?

One argument against this procedure concerns safety. For a long time the FDA said no to this because we did not have safety data, but I believe that objection has fallen away.

Within the past 10 years, this procedure has been performed in rodents and in primates with a lot of success; even human embryos have been made and discarded using these transplant techniques. Although we will want to follow up with these children, I believe we are ready to say that safety concerns, while always a bit of an issue, have been put to rest.

Three-Parent Children

Others say that if we do this, are we somehow creating a child who has three parents—the donor of the mitochondria and the couple who will make the biological child? Personally, I do not find this objection at all moving. We already have sperm donors. We already have egg donors. We even sometimes have embryo donors. Adoption technically leads to a child having more than two parents. I am not convinced that having three parents is going to destroy the American family.

Moreover, even if we are concerned about putting three parents into the picture (or if you can put that to the side), in reality, I am not sure why a mitochondrial donor would have a parental claim anyway. If I owned a car with a good car battery and you had a car with a bad battery, and I decided that I did not want my car anymore and I gave you my car battery, am I now an owner of your car?

Mitochondria, while vital for physiology, are trivial in terms of genetics. I do not believe that you become a parent by donating mitochondria. Thus, this whole notion of a three-parent baby has very little traction.

A Slippery Slope Toward Eugenics?

The last worry is, are we starting down the road to eugenics? Some people worry that because mitochondria will be inherited, this will lead to transplanting not only the genes of the body but the germline genes, genes that will be passed on to future generations.

I am not saying that we need not worry about people trying to make "superbabies," or smarter, faster, taller, stronger babies, but this technique of mitochondrial transplantation has nothing to do with that. First, mitochondrial transplants do not carry that kind of genetic material. Mitochondria do not carry information about our traits or behaviors. Even if one wanted to make a superbaby, mitochondrial transplant is a procedure that is all about cure. It is trying to prevent death, not make mightier, stronger, or somehow all-powerful children.

There certainly is room to debate where we want genetic engineering to go. I would argue that mitochondrial transplant is the wrong place to draw the line. Preventing parents who want to try to have a healthy child who can live does not seem to be the right place to say no to this form of genetic engineering.

I am Art Caplan, at the Division of Medical Ethics at the NYU Langone Medical Center. Thank you for watching.


Comments on Medscape are moderated and should be professional in tone and on topic. You must declare any conflicts of interest related to your comments and responses. Please see our Commenting Guide for further information. We reserve the right to remove posts at our sole discretion.
Post as: