Blog: In the Fast Lane: Genetic Engineering Speeds up

Interim Director of The Centre for Bioethics and Emerging Technology (CBET) at St Mary’s University, Twickenham Dr Trevor Stammers writes on developments in three parent IVF. Last month saw two major steps in the inevitable progress of genetic engineering with or without any ethical framework. On 27th September, the birth in Mexico of the world’s first “three parent baby” was announced in the New Scientist. The picture of the infant being held in the arms of Prof John Zhang, the geneticist who pioneered the technique, was in every major newspaper the next day, but details of the events leading up to the birth were quite sketchy and still are. As Prof Zhang himself seemed keen to emphasise, though two of the baby’s genetic parents were a Muslim couple from Jordan (the identity of the egg donor was not revealed), the mitochondrial manipulation and birth were carried out by a US team in Mexico because “there are no rules” there. Rules might have facilitated further details being revealed as a prerequisite for permission to carry out the procedure. The rules in the UK do permit three parent IVF to be carried out here by a technique called pronuclear transfer - but the Muslim couple in the Mexico case refused this method as it involves the destruction of early embryos. The US team therefore use an alternative method of using a donor egg containing healthy mitochondria which had its nucleus replaced by the nucleus of an egg from the mother who is the carrier of the mitochondrial disease and fertilising this egg – or to be accurate, eggs as five embryos were created only one of which developed normally. We are not told of the fate of the other four embryos but presumably they were discarded. The team waited five months before announcing the birth of the baby boy who, because sperm do not pass on mitochondrial DNA but only nuclear DNA, is currently well but there are concerns that as he grows, the 1% of diseased mitochondria he has in his cells (it is impossible to transfer the maternal nucleus without carrying over some abnormal mitochondria with it) may multiply as he grows. Now that the race to be the world’s first is lost by the UK, scientists here would surely be wise to wait and see if this child remains healthy for the first few years of life before attempting the procedure here? The irony is that the controversial technique of 3 parent IVF could be made obsolete anyway by the rapid developments in gene editing and October saw a Nuffield Council meeting for Q and A on its newly released report on this topic. Gene editing has been known about for decades but it has now become much cheaper and faster due to the advent of a new kind of gene scissors known as ‘CRISPR – Cas 9’ which can be used to cut and replace faulty DNA sequences in the genome. The technique has already been used last year to successfully treat an infant with leukaemia. The process in adults poses no particular ethical dilemmas but its use in embryos again involves embryo destruction - the Crick Institute in London intends to use gene editing to knock out certain genes to observe what effect this has on embryo development. Not surprisingly, the Nuffield Council has chosen to focus on the use of gene editing in reproductive medicine (and its use in modification of animals) as the two topics for their follow up reports due to be released in 2017. The meeting in London was for the most part cautious in its approach, but with one exception. Dr Helen O’Neill, a researcher from UCL chided the meeting for what she perceived as its downbeat mood. Her final slide showed a set of traffic lights and her concluding remark was “I don’t know about you but when I see an amber light, I speed up”. Even in countries where there are rules, it seems there will always be scientists prepared to break them, even if others - be they pedestrians or patients - are put at increased risk as a result. Trevor Stammers Interim Director, Centre for Bioethics and Emerging Technologies