Mitochondrial Transfer (Three-Parent Children)

Edward Leigh Excerpts

Wednesday 12th March 2014 Westminster Hall

[Jacob Rees-Mogg (North East Somerset) (Con)]

I am grateful that the debate has been granted and for the opportunity to serve under your chairmanship, Mr Pritchard. I am delighted that the Under-Secretary of State for Health, my hon. Friend the Member for Battersea (Jane Ellison) will reply, because she is one of the most highly regarded Ministers in Her Majesty’s Government. I would also like to thank my hon. Friend the Member for Congleton (Fiona Bruce) for all her help in preparing for the debate, as well as Dan Boucher, Helen Watt and Luke Gormally.

It is important to begin the discussion by explaining what is at stake with three-parent babies and mitochondria. Mitochondria are the organelles within every cell responsible for the generation of cellular adenosine triphosphate energy. That passes entirely in the maternal line and can carry serious diseases.

There are two means of replacing the mitochondria. Maternal spindle transfer, or MST, takes place before in vitro fertilisation. The spindle, which carries the genes in the nucleus of the egg, is removed from the healthy donor egg and replaced by a spindle taken from the egg of the commissioning mother—that is, the woman at risk of passing on mitochondrial disease. All other parts of the donor egg, including the healthy mitochondria, are left in place. The combined egg is then fertilised by the father’s sperm, and the embryo has three parents: the spindle mother, the egg donor mother and the father. Genetic parenthood is complete in the case of the father but fragmented in the case of the two mothers.

In pronuclear transfer, or PNT, two embryos are created by IVF. One, the embryo of the commissioning women, will have its mother’s affected mitochondrial genes. The other is the healthy embryo of an egg donor. The embryos are combined using a technique somewhat similar to that in the cloning of Dolly the sheep. Interestingly, the licence for the experiment was adapted from the licence originally given for Dolly-style cloning.

[Sir Edward Leigh (Gainsborough) (Con)]

Given that this is obviously an incredibly important matter, akin to cloning, with a child having several parents—I know of no other country in the world that has done this—does my hon. Friend think it should be the subject of a full debate on the Floor of the House?

[Jacob Rees-Mogg]

I certainly think that this matter ought to come to the Floor of the House. I understand from an earlier debate that the Government are committed to full parliamentary scrutiny, but no doubt the Minister will confirm that.

To continue on PNT, at the one-cell stage the donor embryo pronuclei containing the nuclear genes are removed, killing that embryo. The partially gutted donor embryo with its healthy mitochondria is then used to form a new embryo when the pronuclei harvested from the commissioning woman’s embryo are inserted. Harvesting the pronuclei from the commissioning woman’s embryo kills that embryo.

It is important to understand that the techniques are non-therapeutic. They are in no sense a cure for children who are already born, nor do they pretend to be. Rather, the techniques create new people with altered genetic composition—genetically designed individuals who will not inherit mitochondrial disease. Although the mitochondrial DNA is around only 0.1% of a person’s total DNA, a little leaven leavens all the bread, and a different person is thereby created.

The proposed techniques all promote germ-line genetic modification. That is an infinite change that will lead to all the descendants of someone treated in this way being changed, the consequence of which cannot be known.

--- Later in debate ---

[Jane Ellison]

I did not write that brief. I have never used that language and I would not. I accept—indeed, it is right—that this will be a subject of parliamentary debate, because it involves important issues. Just as Parliament has previously debated advances in science, such as IVF, and considered and weighed in the balance the concerns and the potential benefits, so that will happen again. I am certain that people will come to their own conclusion. These matters are normally decided by votes of conscience. I would be very surprised if this matter was not decided in the same way; in fact, I am sure that it will be.

Let me try to respond to some of the points and at least go through the process by which we have got to this point. I should say, though, in response to the intervention that was picked up by colleagues that we will arrange parliamentary briefings with, for example, some of the scientists involved and with the chief medical officer. I hope to be able to give hon. Members the opportunity to put questions directly to some of the people involved. There will be opportunities at all stages along the way, I hope, for colleagues to ask questions and get answers. What they think of the answers will obviously be down to them, but we will try to make it possible for people to come to a very informed view.

I am grateful for this opportunity. I am grateful that hon. Members have had a chance to put some of their concerns on the record, because that helps us in preparing for debates ahead. It gives us a heads-up on some of the areas of particular concern. Obviously, I have also been receiving correspondence about the matter.

The chief medical officer for England announced last year that the Government would go ahead with the development of draft regulations to allow mitochondrial donation in treatment. The consultation began on 27 February and will run until 21 May. I have already recognised the deep sensitivity of these issues. Since we were first approached in 2010 to make the regulations, we have been comprehensively collecting expert opinion and public views, and I will explain how that has been done. However, I understand that for many hon. Members and for many members of the public, this will ultimately be an ethical question. There will be strong views on both sides of the House, as we have seen today.

My hon. Friend the Member for North East Somerset (Jacob Rees-Mogg) touched on what mitochondrial disease is. It is a genetic condition of mitochondria—the part of the body’s cells that produces the energy that they need to function. It tends to be described, for the benefit of the general public, as the “battery pack” that powers a cell.

A person’s mitochondria come from their mother’s egg. Therefore, if a woman has mitochondrial disease, it is likely that she will pass it on to any children she may have. Mitochondrial DNA is separate from an individual’s genomic DNA, which is in the nucleus of the body’s cells. Mitochondrial DNA disease can be devastating, but the disease affects everyone differently. The range of different effects can include heart disease, liver disease, poor growth, loss of muscle co-ordination, visual and hearing problems and mental disorders. Rare conditions caused by faulty mitochondria include forms of Leigh’s syndrome, which can cause multiple symptoms in infancy, such as muscle weakness, heart and kidney failure and nervous system dysfunctions.

Some affected children live short and painful lives. They are constantly in and out of hospital. The quality of life for them and their families is seriously diminished. I have been contacted by a family in that position in my constituency and I suspect that other hon. Members will be as we continue to engage in this debate in the coming weeks and months.

The condition affects approximately one in 5,000 adults, although one in 6,500 babies are born with a severe form of the disease that can lead to death in early infancy. It is estimated that about 12,000 people live with a mitochondrial disease in the UK, and there is no cure. However, research has been ongoing at the Newcastle centre for life, among other places, for many years. In anticipation of significant advances in this field, the Human Fertilisation and Embryology Act was amended in 2008 to introduce a regulation-making power to allow mitochondrial donation to treat serious mitochondrial DNA disease. At the time that amendment was made, Parliament was made aware that there was the potential for these techniques to be developed. The Act was thus amended and that was included.

The mitochondrial donation techniques involve removing the nuclear genetic material from an egg or embryo with unhealthy mitochondria and transferring it to a donor egg or embryo with healthy mitochondria, as my hon. Friend the Member for North East Somerset said.

[Sir Edward Leigh]

Will the Minister give way?