This Baby Has Two Mothers and A Father

An illustration of what was done to produce a baby without Leigh Syndrome (click for credit)
What was done for one couple to produce a baby without Leigh Syndrome
(click for credit)

Modern medicine can do a lot of amazing things these days. Diseases that used to be a death sentence are now not only treatable, but sometimes even curable. Because of the marvels of modern medicine, I have been able to benefit from the company and wisdom of my parents for many more years than I would have if I had been born but a generation ago. However, there are times I wonder whether we should be doing some of the things that modern medicine makes possible. An article I recently read in the journal Science brought that question to my mind once again.

The article describes the work of Dr. John Zhang, the medical director at New Hope Fertility Center in New York, New York. He was working with a couple who had lost two children to Leigh Syndrome, a rare genetic disease that affects the nervous system. While there are different forms of this disease, some of those forms are the result of the mother’s DNA alone. The father’s genes don’t play a role at all.

How is that possible? Most of the cells in your body hold DNA in two different places. The nucleus of the cell contains most of its DNA, which is called nuclear DNA. Half of that DNA comes from your mother, and the other half comes from your father. However, there is a small amount of DNA stored in the cell’s mitochondria, which produce most of the energy that the cell needs to survive. They are represented by the blue, peanut-shaped structures in the illustration at the top of the post. This DNA is called mitochondrial DNA, and you get it only from your mother. As a result, any genetic disease that is produced by mitochondrial DNA is inherited solely from your mother.

This fact allowed Dr. Zhang to produce a baby that is mostly the biological child of the couple with whom he was working, but the baby is also partly the child of a second woman, who served as a donor of healthy mitochondrial DNA.

The basic procedure that Dr. Zhang used is illustrated at the top of this post. The donor provided egg cells. Those cells, of course, held her DNA in its nucleus and in its mitochondria. Zhang then removed the nucleus of that cell and replaced it with a nucleus from the mother who wanted to give birth to the child. The resulting cell had the nuclear DNA of the mother but the mitochondrial DNA of the donor. Because it contained the donor’s mitochondrial DNA, there was no risk of Leigh Syndrome for the child produced from the egg cell. This process was done on 5 egg cells, which were all fertilized with the father’s sperm.

One of the fertilized eggs did not develop, but four of them did. When they were examined, three of them were genetically abnormal. They didn’t have the correct number of chromosomes. However, one fertilized egg was genetically normal, so it was transferred to the mother, who carried the baby to term. The baby was delivered, and according to the abstract of a paper that Dr. Zhang is presenting at a conference:

The baby is currently 3 months old and doing well.

Assuming that Dr. Zhang is telling the truth, this baby boy truly has three parents. Like any other child, his father’s DNA makes up half of his nuclear DNA, and his mother’s DNA makes up the other half of his nuclear DNA. However, the child has another person’s DNA as well. His mitochondrial DNA is not from his mother or his father. It is from the donor. In actuality, however, the boy does seem to have some of his mother’s mitochondrial DNA. According to the abstract of Dr. Zhang’s talk, about 2% of the mitochondrial DNA collected from the baby’s tissues right after birth was from the mother, not the donor.

I really don’t understand this. I realize that people want to have children. However, couples can have children these days even if they aren’t able to get pregnant. My wife and I have a daughter who has no biological relationship to us whatsoever. We adopted her as a teen, but she is my little girl in every way. It doesn’t matter that she didn’t “come from” us. As a result, I have a hard time relating to the couple in this story. Why would this couple go to such much effort, expense, and moral ambiguity to have a child that is biologically related to them? I have never had biological children, but I cannot imagine loving any child more than I love my little girl.

I don’t think this kind of procedure should be done. The fact that the child has DNA from three parents isn’t the issue for me, however. If we don’t understand the relationship between nuclear DNA and mitochondrial DNA, it might become an issue. But for right now, the big problem I have with it is the initial results of the procedure. There were total of five fertilized eggs. One of them was unable to develop, so it might never have been a human life. However, four of them were able to develop into the blastocyst stage. From a scientific point of view, then, they were all human lives. Three of them were discarded, however, because they had the wrong number of chromosomes. As far as I am concerned, then, at least three human lives were snuffed out so that this couple could have a child that is biologically related to them.

I just don’t see how that is justifiable. What do you think?

15 thoughts on “This Baby Has Two Mothers and A Father”

  1. I agree with your assessment, Dr. Wile. For years I was unable to get pregnant. IVF was an option but I couldn’t face discarding or freezing embryos because life begins at conception. Doesn’t the Lord give a soul to every human conceived? Modern medicine is marvelous, but just because we can doesn’t mean we should.

  2. This is so sad! (and disturbing) It’s scary to think where this could lead in the next ten years.

  3. I very much agree with you in terms of the three lives snuffed out. Complete disregard for human life. However, I’m not so sure I agree with you in terms of this being an entirely amoral procedure. It’s a hard one because my instinct is to buck at it and I don’t like the sound of it. But obviously we don’t have clear and potent biblical directive in this case. So I guess what I’m saying is that I’m not sure, but I don’t want to just run with my instant emotional reaction and not try and examine this further. I think you make a fantastic point about adoption though, there is such a need for parents who adopt and I think that shunning that option in the parents from the case study is little more than mind-boggling. Would be interested to hear your thoughts on the morality of it though?

    1. I didn’t mean to give the impression that I think it is an amoral procedure, Martyn. I think it is morally ambiguous, though. I don’t think there is anything inherently wrong about the person having a different set of mitochondrial DNA than the parents. A person with an organ transplant has the DNA of someone other than his or her parents in that organ, and I don’t see anything wrong with organ transplants.

      To me, the immorality is in the death of the other embryos. If you could somehow do this without snuffing out other human lives, I don’t think there is a moral issue here. Of course, that assumes our current understanding is correct and nuclear DNA doesn’t interact with mitochondrial DNA.

  4. I have absolutely no problem with IVF, as long as nobody dies in the process. It grieves me greatly, however, how frequently someone either dies or never is allowed to live in the IVF community.

  5. The Y chromosome is passed nearly unchanged from father to son. The mitochondria are passed nearly unchanged from mother to her children. This is how we can trace lineages.

    Now think how “nearly unchanged” must add up over time if the original mitochondria came from Eve (along with the original cell!), and the original Y chromosome came from Adam.

    This line of reasoning alone makes you think differently about what is possible through adaptation, breeding, and entropy.

    So from my point of view the mitochondria are (or should be) the same in everyone. As you stated, the only concern here is the killing of 4 people.

  6. Interesting article! Thanks for sharing.

    I am curious as to whether you think all fertilized eggs are human or only ones that develop into blastocysts and why?

    1. I think any human fertilized egg that is alive is a human life. The one egg that didn’t develop into a blastocyst might not have been alive at fertilization. The abstract wasn’t clear on that.

  7. I agree with you on this, Jay. Producing and then exterminating human life is, for any reason, not morally acceptable, whether it be giving a couple children, or producing a therapy. Therefore, this procedure is immoral.

    Further, and here again we are in agreement, the motivation for such extravagance is hard to fathom. With so many children in need of adoption, I’d far rather have this money and effort be put to improving the adoption program for adoptive parents. As we move through our foster, then adopt program, we are already feeling overwhelmed with the sheer burden imposed on our family by the government. As we’ve concluded many times up to this point, it really shouldn’t be this hard to help a child in need.

  8. I have a theory that if you spend enough time parenting a non biological child, that child will become yours biologically. I’m not sure of the mechanism but it’s an intuition I’ve had many times.

  9. Lawrence Dol wrote: “the motivation for such extravagance is hard to fathom”. That’s a really good point. Of course, Dr Jay is discreet, but we know that the chance to get famous and receive lots of juicy funding is a less-than-altruistic motive for some of the strange and morally dubious ‘innovations’ in the world of science.

  10. The Lutheran Church – Missouri Synod did a study and paper on fertility issues. As I recall, anything done to have a baby that brought a third person into the marriage was a violation of the commandment, “You shall not commit adultery.” This would include surrogates, sperm donors, and egg donors. I thought that was an interesting way to look at it. So, this procedure would be seen as bringing another person into the marriage.

    To clarify, adoption was not seen as against that commandment.

  11. Dr. Wile… Thank you for always producing such thought provoking articles. You never know where you’re going to end up after reading something of interest. I somehow ended up on the DNA origami Ted Talk of Paul Rothemund, where they show you how to make art with DNA. /paul_rothemund_details_dna_folding?language=en

    I’m sure you’ve seen this.. but I was fascinated and slightly alarmed at the same time. What we can do with DNA is progressing quicky. That talk was in 2008. A youtube video by Nature this year shows 3 dimensional objects with moving parts.. like a box with a lid and latch!

    That programmers have had such luck with DNA is very telling from an intelligent design standpoint. “Reverse engineering” of DNA is in itself a concession to design.

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