'Every time somebody decides to have a baby, they're engaging in a game of Russian roulette,' argues Professor Mary Herbert, a reproductive biologist at the University of Newcastle. Around 60-70 percent of fertilised eggs will never make it to pregnancy. You could see simply being here as a sign that we have beaten the odds.
'We are all survivors – well done,' she congratulates the audience.
Professor Herbert, scientific director of the Newcastle Fertility Centre, presents a clear and concise narrative of her team's research, ultimately resulting in a novel solution of mitochondrial donation for use in the clinic.
Whether an embryo develops into a healthy baby is largely dependant on the DNA inherited from the two parents, she explains. An embryo contains three sets of genetic information or DNA: two nuclear genomes, one from each parent, packaged into chromosomes. The third is present in the mother's ovum in the form of mitochondrial DNA (mtDNA).
Given that the mtDNA consists of only 37 genes you might easily disregard the importance of the genetic information stored here – you would be wrong. Professor Herbert explains that the main function of the mitochondria is to produce the energy required by our cells to survive; the genes encoded in the mtDNA are essential for these processes. When these genes are disrupted by, for example, a mutation, a broad range of debilitating and often fatal conditions can result.
This is where Professor Herbert's own research comes in, on the prevention of the transmission of mtDNA disease by transferring nuclear material to an enucleated donor cell. We have reached the crux of her talk, as she goes into the proof-of-concept investigations her lab did after patiently obtaining a licence from the UK regulator, the Human Fertilisation and Embryology Authority. This took over a year to be granted. It is perhaps a residual lack of patience now that makes Professor Herbert fly through allusions to various ethical considerations and legal hurdles that were necessary to overcome before they could start their investigations.
The work performed by Professor Herbert and her colleagues has also been integral to a change in UK law to permit the use of mitochondrial donation within the clinic. Here the talk would have benefited from a more thorough discussion of these areas, allowing the viewer a further understanding of the considerations for and against as well as the potential real-world impact of the group's work.
With the aid of an illustrative video of the kind of microsurgery they conduct in the lab, we watch as the almost invisible pronuclei are evacuated from the cell of a carrier and carefully injected into the cell of a healthy donor. A remarkably high proportion – 95 percent – of these injected cells survive. This technique proffered by Professor Hubert and her colleagues allows potential mothers who are known carriers of disease-causing mtDNA to have genetically related children without the risk of passing on the condition.
Professor Herbert continues her talk, introducing the idea of so-called three-person babies, which emerged during a period of intense media interest in their work. This notion is dismissed by Professor Hubert as a misnomer since the mtDNA that is provided by the third individual (an egg donor) does not contain DNA that would encode any of the characteristics considered responsible for making an individual unique.
Her straightforward pronouncement of this argument is clearly reflective of her opinion on the ethical implications of their research. It would have been more interesting, had Professor Herbert gone into more detail on the questions and conflict that this unprecedented media coverage created.
Professor Herbert's fact-driven and frank presentation was brought into perspective as she recounts meeting a woman of a similar age to herself, fast succumbing to a mitochondrial disease. The woman found it 'deeply consoling' that her daughters' lives would not be blighted by the fear of transmitting it to their children, she told Professor Herbert.
The talk finishes by thanking the many women who have generously donated their eggs in order to, 'give the gift of health not just to one child but to generations of children to come'. This new and extraordinary treatment grants us the ability to not simply treat a single child, but to effectively eliminate the disease.
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