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Mitochondrial replacement likely to be safe but more research needed, says report

9 June 2014
Appeared in BioNews 757

Two experimental IVF techniques that could prevent certain types of incurable genetic disease are 'not unsafe', a report from the UK's Human Fertilisation and Embryology Authority (HFEA) has found.

Mitochondrial replacement (MR) involves transferring genetic material from a fertilised or unfertilised egg cell with faulty mitochondria into a healthy, denucleated egg cell provided by a donor, effectively creating embryos with genetic material from three people.

Mitochondria primarily provide the energy needed in each of the body's cells to enable them to function. Mutations in mtDNA (mitochondrial DNA), however, which only accounts for one percent of a person's genetic code, can cause debilitating and often fatal diseases. As mtDNA is exclusively inherited from the mother, women with disease-causing mutations within their mitochondria are at risk of passing on health problems their children.

The report was the HFEA's third review of the safety and efficacy of MR techniques being developed to prevent the transmission of serious mitochondrial disease.

It found that the two MR techniques being developed, maternal spindle transfer and pro-nuclear transfer, were potentially useful for a 'specific and defined group of patients', namely those with unhealthy mitochondria at risk of passing on health problems and who want to have genetically-related children.

The evidence reviewed 'did not suggest these techniques were unsafe', the report concluded, a finding also made in the previous two reviews. It also found that research into MR had 'progressed well' but that there are still a number of experiments that needs to be carried out before treatments are offered to patients.

Professor Robin Lovell-Badge, from the Medical Research Council and a member of the scientific panel, said: 'The direction of travel still suggests that it is all safe, but we don't know what's round the corner so we're being a little cautious'.

The development of MR techniques has also attracted ethical concerns. Human Genetics Alert has warned it could lead to a 'risk of a consumer eugenic market' in 'enhanced designer babies'.

However, scientists have argued that the mitochondrial DNA will have no impact on the characteristics of the embryo apart from the function of the mitochondria itself, and thus does not constitute a form of 'eugenics'.

Dr Andy Greenfield, the panel chair, addressed these concerns saying: 'This is not eugenics [...] eugenics it seems to me invokes preventing some individuals being born. [...] These technologies will allow women to have genetically related and healthy children'.

Even if MR techniques are proven to be safe, as the technique involves changing the DNA of a human embryo, their use remains prohibited under UK law. However, Parliament is able to pass regulations to permit the technique under the governing legislation.

The UK government has in principle backed the use of MR and has conduced a consultation on draft regulations (reported BioNews 744). The chief medical officer, Professor Dame Sally Davies, commented last year, 'It's only right that we look to introduce this life-saving treatment as soon as we can'.

Sally Cheshire, chair of the HFEA, said: 'Now it is a question for others. If the Government decides to seek to change the law they will need the approval of both Houses of Parliament, and it is only right that they consider all the ramifications, social as well as medical, before they make up their minds.

'There is a long way to go yet'.

Sarah Norcross, the director of the Progress Educational Trust, which publishes BioNews, said: 'The scientific review committee have given a considered thumbs up to allowing techniques to avoid the transmission of inherited mitochondrial disease to be used in clinic.

'We therefore urge the Government to press ahead and pass regulations to allow families blighted by mitochondrial disease to benefit as soon as possible'.

Genetic treatment using three-parent embryo may be ready in two years
The Guardian |  3 June 2014
HFEA publishes report on third scientific review into the safety and efficacy of mitochondrial replacement techniques
Human Fertilisation and Embryology Authority (press release) |  3 June 2014
Review of scientific methods to avoid mitochondrial disease - 2014 update
Human Fertilisation and Embryology Authority |  2 June 2014
Three-parent babies are 'not unsafe' as human trials planned
The Telegraph |  3 June 2014
Three-person babies 'in two years' - says science review
BBC News |  3 June 2014
Three-person IVF in 'two years'
NHS Choices |  5 June 2014
U.K. Report Says Proposed IVF Technique Is Likely Safe
ScienceInsider |  3 June 2014
19 June 2017 - by Shaoni Bhattacharya 
The fertility doctor who led the team which produced the world's first baby through mitochondrial replacement therapy is now looking to use the same technique in a commercial venture...
15 February 2016 - by Dr Peter Mills 
The US NAS has published a report on the ethical, social and policy considerations relating to mitochondrial replacement techniques. The recommendation that has inevitably attracted most attention, however, is that only male embryos should be transferred, an approach that was considered but rejected in the UK...
12 January 2015 - by Dr Rachel Montgomery 
Regulations to legalise and govern the use of mitochondrial donation techniques have been placed before the UK Parliament....
4 August 2014 - by Siobhan Chan 
The UK Government has been accused of deliberately misleading the public in order to win approval over its plans to implement mitochondrial replacement techniques in IVF...
28 July 2014 - by Dr Rachel Montgomery 
The UK Government has announced that regulations around the use of mitochondrial replacement techniques will be presented to Parliament in the next few months...
17 March 2014 - by Dr Louisa Petchey 
The Conservative MP for North East Somerset, Jacob Rees-Mogg, has said that mitochondrial donation will produce 'genetically modified children' with 'three parents', and was 'effectively cloning'...
3 March 2014 - by Patricia Cassidy 
The UK Department of Health has published draft guidelines for the use of new techniques to prevent mothers passing on serious mitochondrial diseases to their children. The guidelines will be the subject of a three-month consultation...
14 October 2013 - by Dr Rosie Morley 
A group of European parliamentarians has criticised UK proposals to legislate for mitochondrial replacement therapy, calling it 'a eugenic practice'...
23 September 2013 - by Dr Rosie Morley 
A group of scientists has expressed concerns that it may be too soon to bring mitochondrial replacement techniques, which are still under development, to the clinic....
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