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Three-person IVF may be trialled in the UK as soon as this year, after getting the final go-ahead from the UK’s fertility watchdog. Having been made legal in the UK in 2015 after a lengthy series of consultations into the safety and efficacy of the technique, the Human Fertilisation and Embryology Authority (HFEA) has now recommended the mitochondrial transfer technique be approved for “cautious” use only when there is a high risk a baby conceived without the intervention will be gravely affected. The HFEA has approved mitochondrial donation - as a result, clinics can now apply to the fertility regulator for a license to use the technique, and the HFEA will approve every clinic and patient individually.
“This is probably the most comprehensive review of the scientific research into mitochondrial donation undertaken by anyone, anywhere...” said Andy Greenfield, panel chair and HFEA board member. “We think that the cautious approach to the use of mitochondrial donation in treatment that we recommend strikes the right balance between offering access to this exciting new treatment to couples at real risk of having a genetically-related child with mitochondrial disease, while doing all we can to ensure that the treatment is safe and effective.”
HFEA chair Sally Cheshire added: “While the detail is fiercely complex, the reason behind all the hard work done by the panel over four reviews is very simple: helping future generations of children to live happy and healthy lives."
Expert Robin Lovell-Badge told the BBC the only thing left to do now is to trial the technique - the UK’s regulator and scientists have done all they can to prepare for the technique. He also recommended there be extra checks throughout a pregnancy.
History was made in 2016 when a baby boy was born with genetic information from three people in Mexico. And on 5 January, 2017, a baby girl was born with DNA from three people in Ukraine in the first ever use of a technique called pronuclear transfer.
Confused? Here’s everything you need to about the novel in-vitro fertilisation technique.
The technique is specifically aimed at couples that want a biological child of their own, but who would almost certainly pass on a sometimes fatal genetic disorder without intervention.
No, the technique is aimed specifically at those with mitochondrial disease. This is a catchall term for a range of conditions that directly impair our mitochondria.
Mitochondria are present in almost every cell in the body and are responsible for converting the energy from food and oxygen into the energy that powers our cells. Essentially, they power the entire body - or at least, are responsible for producing about 90 percent of the power.
If they are not working properly the cells can die, and heart, brain, muscle and lung function can be severely impaired. The United Mitochondrial Disease Foundation lists symptoms that include strokes, seizures, blindness, deafness, diabetes and muscle failure.
The individual might have gastrointestinal problems, a poor immune system, or problems with their kidney and heart function. In many cases, it is impossible to tell how severe the impact will be, but it can be deadly. This was the case for the couple that has become the first on record to undergo the novel IVF technique. The mother carries genes for Leigh Syndrome, which affects the nervous system, and had already suffered the loss of two children born with the syndrome.
Because it works by swapping the mother’s mitochondrial genetic information with that of a healthy donor’s.
Dont panic. Most of our genetic information is carried in chromosomes. However, mitochondrial DNA contains 37 genes, all of which are related to producing energy in the cells. Three-person IVF is about taking all the genetic information of the mother and father, and only removing the mitochondrial DNA contributed from the mother.
There are three approaches: pronuclear; maternal spindle transfer; and nuclear genome transfer. Pronuclear uses a one-day-old embryo created from the parents’ sperm and egg, and replaces its nucleus with one taken from an embryo made using a donor’s egg and the father’s sperm. The result is an embryo made up of nuclear chromosomes from the parents containing 99.9 percent of the DNA, and healthy mitochondrial DNA from a donor woman.
Maternal spindle transfer (MST) was the technique used by the New Hope Fertility Center in New York which led to the birth of the first three-person IVF baby this year. It involves replacing the nucleus of a donor egg with a nucleus removed from one of the mother's eggs.
Nuclear genome transfer is far more experimental and is very similar to MST, but the egg is not fertilised.
It was legally approved in the UK in 2015 after years of debate and research. A Nature study published in June 2016 found the technique would lead to normal pregnancies.
The procedure has not been approved in the US, though a committee of the Institute of Medicine is investigating its ethical and social implications. As a result, the child born using the technique this year was in fact conceived through IVF that reportedly took place in Mexico, where there are no legal rulings on it.
The baby born in Kiev, Ukraine in January was born using the alternative pronuclear transfer technique explained above, and a second baby from a different couple is expected to be born from the same technique in March. It is not just the second time a baby has been born with DNA from three people, however. It is the first time a baby has been born using the technique where there is no risk whatsoever of mitochondrial disease.
The Nadiya clinic in Kiev underwent the procedure to help a couple that could not conceive. In the UK, the pronuclear transfer technique is less well developed and is therefore not in use, and there have been no ethics debates around using three-person IVF to help healthy people conceive.
“There is little or no evidence to support the use of mitochondrial transfer to improve egg or embryo quality or reverse egg ageing," Dr Jane Stewart, secretary of the British Fertility Society (BFS), told WIRED, when asked about the likelihood of the practice being used for standard IVF. "There is certainly not enough research evidence available to justify its use in the clinical setting for improving IVF outcomes."
The technique raises a host of ethical questions, from the discarding of embryos resulting from the pronuclear technique, to the concept of “designer babies”. But concerns have also been raised about medical risks that may come with it. These range from the potential for tiny amounts of mutated mitochondrial DNA being transferred to the embryo, to signs of malformations recorded in some animals models. However, the June Nature study did thoroughly investigate the procedure, looking at more than 500 eggs from 64 donor woman, and found the embryo developed normally.
A more recent study published on November 30, 2016 in Nature has showed that embryos created from four women who were at high risk of passing on the disease, could still pass on the mutation even using the technique. It was concluded that defective mitochondria can still develop in one out of eight babies.
Co-author on the study, Doug Turnbull, director of the Wellcome Trust Centre for Mitochondrial Disease at Newcastle University, did add this disclaimer: "Our studies on stem cells do express a cautionary note that it might not be 100 per cent efficient in preventing transmission, but for many women who carry these mutations the risk is far less than conceiving naturally."
This article was originally published by WIRED UK
