Three-parent embryos a step closer to reality after UK Government declares them safe

by jeeg 4. June 2014 19:41


The prospect of creating IVF embryos with genetic contributions from three people has come a step closer with the Government’s fertility watchdog concluding that there are no scientific reasons to believe that the technique is unsafe.

An exhaustive review of the scientific literature has found that transferring mitochondria from one woman’s egg to another to create a “three-parent” IVF embryo is “not unsafe” and should therefore be considered for women with specific genetic disorders who desire their own children.

The findings support the call for the Government to swiftly introduce legislation, perhaps as early as this year, to allow mitochondrial transfer for women who carry defective genes in their mitochondria – the tiny power packs of the cells.

It is the third scientific review of mitochondrial transfer by the Human Fertilisation and Embryology Authority (HFEA) and none of them has found scientific justification to continue with the current ban on mitochondrial transfer to treat serious diseases.

“The science is complex, but the aim is simple: to enable mothers to not pass on to their children a range of serious, and sometimes fatal, inherited conditions,” said Sally Cheshire, the chair of the HFEA.

An expert panel convened by the HFEA found no substantial problems with the two broadly similar techniques that would result in the transplant of healthy mitochondria from a donor egg into the egg of a woman carrying mutations that could result in mitochondrial illnesses in her children.

“The panel has examined, discussed and re-examined data from disparate fields of science, including biochemistry, evolutionary biology, the genetics and developmental biology of model organisms and, of course, clinical genetics and embryology,” said Andy Greenfield of the Medical Research Council’s mammalian genetics unit, who chaired the HFEA panel.

Mitochondria carry their own genes and so any transfer from a donated egg will result in small genetic changes to subsequent generations as mitochondrial DNA is passed down the maternal line. Some commentators believe this is a form of “germ-line” genetic engineering that could be the slippery slope to so-called designer babies. 

“The international community is wholly against these techniques. The UK would be setting a very dangerous precedent in adopting them and isolating itself from the rest of the world,” said Fiona Bruce MP.

“Many MPs are gravely worried about the safety of these proposals, the fact that they have not be properly tested, and the very real risk that they could open the door to designer babies,” Ms Bruce said.

Lord Alton of Liverpool said “Given the safety concerns which have been raised, the unresolved ethical questions, and a practice which runs contrary to international consensus, it would be prudent for the UK to wait at least until these issues have been resolved before being stampeded into a decision which has such far reaching consequences.”

However, many fertility specialists believe that the benefits of the procedure outweigh any risks that may be attached to the technique, which so far has only been tried on laboratory animals and is prohibited in most countries with fertility legislation.

Professor Peter Baude, a fertility specialist at King’s College London and member of the HFEA panel, said: “Implementation of any new medical treatment is never wholly without risk, and the genetic alteration of disease is an important step for society that should not be taken lightly.”

Steve Connor, The Independent


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