On 3 Feb 2015, the British Parliament voted 382 to 128 in favour of legalising a technique in assisted reproductive technology known as mitochondrial replacement, after much heated debate. The UK is the first country in the world to legalise this treatment that would result in children with three genetic parents.
Speaking in support of this controversial legislation, UK Prime Minister David Cameron asserts: “We are not playing God here, we are just making sure that all parents who want a healthy baby can have one.”
Mitochondrial replacement is a technique that purportedly would allow women with mitochondrial diseases to have healthy children. Dysfunctional mitochondria inside cells – caused by mutations in the mitochondria DNA (mtDNA) – can result in serious health problems such as neurodegenerative disease, blindness, deafness, muscular dystrophy and diabetes, and could even lead to death.
Researchers think that replacing the disease-linked mtDNA with healthy mtDNA would prevent the transmission of the defective mitochondria to the offspring. While there are a few ways of doing this, the technique that is legalised in the UK is called maternal spindle transfer.
This technique requires an egg donor who is free from mitochondrial disease. The cell nucleus (or the spindle of chromosomes) is removed from the unfertilised healthy donor egg and replaced by the cell nucleus of the mother (i.e., the woman suffering from mitochondrial disease). The resulting ‘combi-egg’ with healthy mitochondria is then fertilised invitro by the sperm of the father. The advantage of this technique is that the social parents could also be the genetic parents.
While Christian theologians and bioethicists recognise the plight of women with mitochondrial disease, they have serious concerns about this treatment because of the many ethical and social issues it raises.
An important issue associated with this procedure is that the child would have three genetic parents. Some scientists, however, have tried to downplay the significance of ‘thirdparty’ mitochondria in a person’s genetic makeup. They assert that third-party contribution is inconsequential since the egg donor who provides the healthy mtDNA provides just 0.1 per cent of the genetic make-up of the child.
However, the fact remains that in maternal spindle transfer, the genes of two women are mixed as the nuclear DNA from the mother’s egg and the donor’s mtDNA are housed together. Thus, the embryo in fact carries a paternal DNA code and two partial maternal DNA codes. As François Baylis points out, “while it is undeniably true that the egg provider who contributes the healthy mtDNA provides less than 0.1 per cent of the total genetic make-up of the newborn, this fact is irrelevant to the accuracy of the claim that there are three genetic parents”.
Even if the success rate of mitochondrial replacement technology is reasonably good (and it’s simply too early to offer an assessment at this stage), questions about safety must still be taken seriously. As A. Bredenoord and P. Braude have candidly put it, we simply “do not know … whether a mixture of mtDNA from two different origins is safe”.
Here, safety has to do not only with the child in question but also with future generations. With mitochondrial replacement technology, the mtDNA of a third-party donor will be passed from women to their children. Female children will in turn pass this donor mtDNA to their children, down the female line. The long-term consequences of this are simply not known at this point.
Aside from the risks involved in the procedure, egg donation itself poses some serious ethical issues in addition to that of the commodification and even commercialisation of women’s bodies. Egg donation also raises questions about the relationship between the donor and the child. These questions apply even though only the mtDNA of the donor egg is used, as is the case with maternal spindle transfer.
Philosophical questions like how such procedures alter our perception of the child, often not addressed in the literature, must also be pressed because of their profound social ramifications. In maternal spindle transfer, the child-to-be is put together like a collage, using genetic materials from the eggs of two different sources in a process that is not dissimilar to an assembly line. The end result is the product (and triumph!) of homo faber (Latin for “Man the Creator”).
More is at stake in mitochondrial replacement technology than simply fulfilling the wishes of parents who want to have a healthy baby. As science and technology advance, the ethical issues raised become correspondingly more profound and ramifications more far-reaching. Society must never respond to these difficult challenges with simple clichés and naïve pragmatism.
“Soundings” is a series of essays that, like the waves of a sonogram, explore issues in society, culture and the church in light of the Gospel and Christian understanding.
Dr Roland Chia is Chew Hock Hin Professor of Christian Doctrine at Trinity Theological College and Theological and Research Advisor at the Ethos Institute for Public Christianity (http://ethosinstitute.sg/).