Is It Ethical to Create Babies From Three DNA Sources? Absolutely

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The House of Commons in the U.K. has now voted to permit mitochondrial DNA replacement, which enables babies to be born who have DNA from three people.

Mitochondria are the batteries of our cells that provide energy for cell division and growth. We get ours from our mother’s genes. If there is a defect in a mother’s mitochondria, it can have devastating consequences for her children, resulting in almost certain death. But, by extracting a mitochondrion from a healthy donor egg, scientists are now able to conduct a miniature organ transplant on the cellular level to create a healthy baby through in vitro fertilization. Such a baby has its parents’ genes, except for one small but crucial portion obtained from a donor.

Arthur Caplan

Arthur Caplan is the Drs. William F and Virginia Connolly Mitty Professor and founding head of the Division of Bioethics at New York University Langone Medical Center in NYC. He is one of the nation’s top medical ethicists.

If the House of Lords also approves, Britain will be the first nation to authorize the procedure. The United States is studying the mitochondrial transplants. A series of meetings began last week at the Institute of Medicine at the request by the Food and Drug Administration.

The need for the procedure is real. Somewhere around 4,000 children per year in the United States are born with a type of mitochondrial disease. Many do not survive more than a few months. Mitochondrial transplants would help prevent these diseases. So why not use them?

Critics give three main reasons; safety; creating babies with three parents; and the danger of opening the door to more genetic engineering. None of these objections provides a convincing reason against trying to treat what are often lethal diseases.

Is the procedure safe? When it was first tried by my NYULMC colleague, Jamie Grifo, at NYULMC in 2003 he was widely denounced as doing something unsafe with an embryo. The FDA brought his work to a halt. Grifo said he had plenty of data in rodents to show the technique was safe but decided not to push against the FDA’s opposition. So what is different now that makes safety less of an issue?

Now we have data from monkeys. Convincing data. The creation of healthy primates was shown in 2009. And we have data from the creation of human embryos. A team of scientists at the Oregon National Primate Research Center and the Oregon Health & Science University proved in 2012 that the transplanted mitochondria made viable embryos. Safety is always an issue but the case for moving forward in the UK and the USA is strong.

Some say three parent babies are weird. It is true that a mitochondrion is taken from a donor but why this makes the donor in any way a parent is beyond me. If I give the battery from my car to a friend whose battery has died does that make me an owner of her car? And even if logic were stretched to say yes, it is not as if this is the first time we have seen babies with three parents. Sperm, egg, and embryo donation and surrogacy—not to mention adoption—have been around a long time without fracturing the nature of the family. This objection gets no traction.

Lastly some say mitochondrial transplants cross a bright ethical line. Changing genes in the lungs of people with immune disease or in the eyes of people with macular degeneration may fix the broken body part but, critics point out, the change is not passed on to future generations. When you change the mitochondria in an egg with a transplant, you make a change that is inherited by every single offspring of any child created from that egg. That is called germline engineering. Germline engineering of mitochondria moves beyond using genetic engineering to fix our body parts into directly engineering the traits of our children. It is a road that could lead, the critics warn, to eugenics.

Well, that’s where they are wrong. Transplanting mitochondria is not going to be the method used to create enhanced babies. Traits like height, intelligence, strength, balance, and vision don’t reside in the battery part of our cells.

We may well want to draw the line at genetic engineering aimed at making superbabies but all that is involved with mitochondria transplants is trying to prevent dead or very disabled ones. The latter goal is noble, laudable and ought to be praised not condemned.

There are some reasons to worry about mitochondrial transplants. Mainly that they might not work. Other concerns are not persuasive. Britain should lead the way and the USA and other countries should follow in giving this technique a green light.