The Ovolution of the Three-Parent Embryo

June 17, 2012 • Posted in Blog

By D. Joy Riley, M.D., M.A.

Executive Director

The Tennessee Center for Bioethics & Culture

The United Kingdom presented the rest of the world with Louise Joy Brown in July, 1978, the first test-tube baby. They convened what became known as the Warnock Committee to advise Parliament regarding the new reproductive technologies: “what policies and safeguards should be applied, including consideration of the social, ethical, and legal implications of these developments, and to make recommendations.” (Warnock, A Question of Life, 4.) The Warnock Committee by a slim margin approved a variety of reproductive adventures, including research on the embryo up to day 14 post-fertilization. That was an arbitrary date, chosen to hopefully avoid pain sensation by the embryo. Embryos should only be handled by those licensed to do so; and the supervisory licensing body must be headed by a lay-person, the committee opined. Additionally, no embryo used for research should be implanted. These recommendations became the basis of the Human Fertilisation and Embryology Act of 1990 (HFE Act), and the licensing body, the Human Fertilisation and Embryology Authority (HFEA), came into being in 1991.

A few years later, the UK was in the spotlight again, when “Dolly,” the cloned sheep stepped onto the stage. It was time for another committee to react to another advance, and a consultation (asking the public’s — or a portion thereof — opinion) was held. There was concern about the public’s reaction to the word “cloning,” so the terms used to solicit public opinion were “nuclear replacement technology” and “new techniques which might be developed to treat serious medical conditions.” (Human Genetics Advisory Commission and the Human Fertilisation & Embryology Authority, “Cloning Issues in Reproduction, Science, and Medicine,” A Report, December 1998) Could it be a surprise that the consultation showed people in favor of “nuclear replacement technology”?

The next link in this “ovolution” occurred in November 2006, and involved animal-human hybrids. Two research teams applied to the HFEA for licences “to derive stem cells from human embryos.” Citing a shortage of human eggs, the investigators proposed “using animal eggs, from which they had removed almost all the animal genetic material (DNA). These embryos would be a kind of hybrid, known as a cytoplasmic hybrid embryo.” (http://www.hfea.gov.uk/519.html) What should the HFEA do? A consultation would help decide matters. A consultation was duly held, from April to July 2007. The results? “The Authority at its September 2007 meeting considered the detailed findings of the consultation and agreed a policy for the licensing of cytoplasmic hybrid research.” (http://www.hfea.gov.uk/519.html).

So the stage has been set. In vitro fertilisation (IVF) birthed more than Louise Joy Brown and the more than four million babies born through IVF since that time. The evaluating committee approved embryo research for a variety of reasons. Dolly the sheep appeared, and the advent of human cloning was scary. Therefore the language was altered, and nuclear replacement technology was approved. Women did not line up to donate eggs for this enterprise, so the possibility of combining human genomes with animal eggs was conceived. Take the nucleus out of an animal egg, and replace it with a human cell nucleus: voilà! A human-animal hybrid.

Now the next step can occur: take a human egg from one female, and replace its nucleus with the nucleus of a different human female’s egg, then fertilize the egg, and transfer it to a uterus. Briefly, the combination is of the donor’s egg cytoplasm (with normal mitochondria), the mother’s egg nucleus; and the father’s sperm. No one is calling this a human-human hybrid. No; it is called hope for those families suffering from mitochondrial-linked diseases.

Mitochondria are like cellular batteries, and they carry their own DNA. They have 37 genes, of which 13 seem currently to be of the most interest. The difficulties associated with mitochondrial diseases are real and varied, afflicting about 100 children per year in the UK. Since mitochondria are only passed down from mother to child, scientists have seized on this idea of replacing the faulty mitochondrial DNA of the mother with the non-affected mitochondrial DNA of an egg donor. The resulting child would have the chromosomes of his/her mother and father, and the mitochondrial DNA of the egg donor. The Nuffield Council on Bioethics has, after some study, declared this “ethical.” According to the BBC,

Dr Geoff Watts, who led the inquiry, said: “If further research shows these techniques to be sufficiently safe and effective, we think it would be ethical for families to use them if they wished to, provided they receive an appropriate level of information and support.”

Several questions have been raised about the three-parent embryo. One is, will the egg donor be a parent to the child? According to the HFEA, the answer is, “No.” Dr David King, director of Human Genetics Alert, voiced his concerns:

“Just as Frankenstein’s creation was produced by sticking together bits from many different bodies, it seems that there is no grotesquerie, no violation of the norms of nature or human culture at which scientists and their bioethical helpers will balk.

“The proposed techniques are both unnecessary, and highly dangerous in the medium term, since they set a precedent for allowing the creation of genetically modified designer babies.”

He argued that such techniques would affect many generations and crossed “what is normally considered the most important ethical line in the prevention of a new eugenics” and this was “precisely how slippery slopes get created”. (http://www.bbc.co.uk/news/health-18393682).

Before this can occur, however, the HFEA will hold a consultation, beginning in September, and will release the results in 2013. At least one news report has outlined the required next steps: “Then the government regulator, the HFEA has to approve the technique and then there would have to be a parliamentary vote to change the law because this kind of technique is currently illegal.” (itv) The expected outcome is clear, even if the risks or effects of these experiments are not.