British Bioethics Council Gives OK to Three-Parent Embryo

Bioethics   |   Rebecca Taylor   |   Jun 14, 2012   |   1:57PM   |   London, England

A British ethics committee has recommended going forward with creating human embryos with 3 genetic parents. The Nuffield Council on Bioethics, an independent body that considers issues in biotechnology and medicine, has found the genetic engineering technique is ethical and should move forward even though the technique is currently against the law in the United Kingdom.

Why would doctors want to engineer an embryo with the genetic material from 3 people? Because, it will “prevent” the inheritance of mitochondrial disease. Not all of our DNA that we inherit is in the nuclei of the egg and sperm that join at fertilization. In the cytoplasm of our mother’s egg are mitochondria. Mitochondria have their own DNA called mtDNA. We inherit our mtDNA only from our mother because sperm’s mitochondria are dumped at conception. There are genetic mutations that cause very serious disease found in mtDNA and a woman with a such a mutation cannot help but pass this mutation on to her children.

This is where the three parent embryos come in.

There are two different ways to approach the making of a embryo with 3 genetic parents. In the first method, called pronuclear transfer, doctors would take the nucleus out of an embryo that had a mutation in his or her mtDNA and put it into an embryo whose mtDNA was normal, after removing the nucleus of that embryo of course. (For an illustration of this method click here.) The alternative method, called maternal spindle transfer, would be to remove the nucleus of an egg from a woman with mitochondrial disease, place it into a donor egg with normal mtDNA (after the nucleus of that egg was removed) and then fertilize the engineered egg with sperm. (The Nuffield Council has a description and current state of research for both pronuclear transfer and maternal spindle transfer.) In either technique, the result is an embryo with the nuclear DNA from its mother and father and the mtDNA from another woman.

The Nuffield Council on Bioethics has determined that either technique would be ethical. The problem is that this kind of genetic engineering would be inherited not just by the child produced, but also by every generation after. This is called a germ-line modification which is currently against the law in the UK. From Reuters:

Three-parent” fertility treatments designed to prevent some incurable inherited diseases would be ethical and should go ahead as long as research shows they are likely to be safe and effective, a British medical ethics panel said on Tuesday.

The Nuffield Council on Bioethics said the treatments – which have become known as three-parent in vitro fertilization (IVF) because the offspring have genes from a mother, father and from a female donor – should be offered to affected families together with full information and expert support.

“If these treatments are successful, these children would be among the first in the world to have a genetic connection to not two people, but three people,” said Geoff Watts, who chaired a Nuffield inquiry into the issue. “There are a number of ethical questions that arise and needed to be considered.”

“If further research shows these techniques to be sufficiently safe and effective, we think it would be ethical for families to use them … provided they receive an appropriate level of information and support,” said Watts.

Although mitochondrial DNA swapping is not the same as altering the DNA inside a cell’s nucleus, the Nuffield inquiry concluded it was nevertheless a form of germline therapy. But Watts stressed this did not mean the ethics body would approve any other forms of germline therapy, which are currently banned in Britain.

“Some people concerned about the idea of germline therapies may fear that if such treatments for mitochondrial gene disorders were approved, a slippery slope would be created towards comparable alterations to the nuclear genome,” he said.



Curing mitochondrial disease is a laudable goal. But this is not the way to do it. Both proposed techniques create and manipulate human life in a dish. The first creates two embryos, destroying one to make a hybrid third. I wonder how many embryos have to be destroyed to have one success. The second manipulates the egg and then creates an embryo with an altered egg. And while this method would be less morally objectionable than the first, it still requires that life be created in a lab and not in the best, safest and most loving place: inside a mother’s body.

Secondly, the Nuffield Council said this would be ethical if these techniques could be shown to be “safe and effective.” And how will that happen? Eventually by testing them in humans. The children that result from this germ-line genetic engineering would be walking experiments. Not that this would be an unusual situation for IVF children, since the long term effects of being conceived in a dish are still being determined. But, in this case, genetically engineering embryos to have the genetic material from 3 people and then seeing how they turn out is, without a doubt, human experimentation without the consent of those being experimented on. I fear what the Nuffield Council does not: a slippery slope to all kinds of other germ-line genetic engineering and modifications of countless generations without their consent.