The 'three parent baby' debate

The UK's House of Commons voted by 382 to 128 - a majority of 254 - to allow mitochondrial donation through a controversial amendment to the 2008 Human Fertilisation and Embryology Act (HFEA).  The regulations will now have to be approved in the House of Lords, where they are likely to be passed.

Kat Arney spoke with Fertility expert Robert Winston...

Robert - Actually, we're not the first country to permit mitochondrial transfer. It's already been done in the United States 20 years ago and we haven't permitted it in the UK yet. We have two houses of parliament and it hasn't gone through the House of Lords. Hopefully, it will and then there'll be a possibility of getting a license. But it's not permitted in the UK at the moment.

Kat - So, if we can unpick a bit about the science of this, people have referred to this as mitochondria. What are a mitochondria and what's gone wrong with them?

Robert - Mitochondria are tiny dots of material in most cells in the body and they are responsible for providing the energy which drives a cell. And so, they are involved with various chemical reactions, which include the Krebs Cycle, which in fact generates the way that we make energy. They contain about 16,000 base pairs of DNA. So, there's a tiny amount of DNA in those cells.

Kat - Because we have 3 billion, that's the rest of our genome.

Robert - We have 3 billion, so that's about 0.001% of your DNA is actually in your mitochondria.  These mitochondria in nowhere as far as we know have anything to do with your personality or being how you are. The so-called phenotype, as we see it normally, when we look somebody or when we talk to somebody, your strength, your beauty, your intelligence, your memory and so on.

Kat - It's just the energy factories.

Robert - Just the energy factory.

Kat - A lot of bit has been said about women who have children with this mitochondrial disease, because it's only the women's egg cells that have these mitochondria that then go to the next generation.

Robert - Well actually, that's probably untrue too because it's probable that a sperm have mitochondria, but nobody ever mentions that. But they don't seem to get into the egg actually. There are a whole other things about mitochondrial disease which are being extraordinarily discussed over the last few weeks. 

First of all, I think that the whole issue of mitochondrial transfer is much more trivial than has been generally stated. I think that it's probably been rather unwise to attract the amount of publicity it has done because it's bound to bring out all the people who are hostile to in vitro fertilisation. But basically, there are a few people- actually, it's really quite rare - who have mitochondrial disease and they suffer from gradual decreasing of brain activity, loss of muscle power, loss of kidney and heart function. Many of these people die as children often before the age of 4. Sometimes they grow into adults and they have a form of muscular dystrophy or blindness or other very serious disorders. These diseases are horrible and there's no way of caring them. Once you've got them, there's no chance. 

So, what has been proposed is that mitochondrial transfer should be done by taking out the nucleus and putting it into the cell with fresh mitochondria, alternatively transfusing mitochondria into the cell where the nucleus already is having got rid of the old mitochondria. And this is what the license is being applied for my colleagues in Newcastle.

Kat - So, this is I guess where the idea of the 3 people involved. I know a lot of people say these aren't 3 parent embryos that there's from one woman's egg cell, you're taking these mitochondria, the energy factories and then you're mixing it with the DNA from the two biological parents.

Robert - But you are more of a 3-people person when you've had a blood transfusion because you've had hundreds of cells, complete cells from another individual. Their only difference is that the mitochondria persist that they go on dividing and they live indefinitely and they pass on to the next generation. That's the difference. 

So, you potentially have a permanent cure. The probability is that - the difficulty of course is that we don't know whether this is going to happen because there's no animal model. So at the moment, we're still hoping to do this. But there are a number of desperate mothers and fathers out there who would not want to see another child die, who feel very strongly that they should be given the autonomy to do this. And so, consequently, I think that it will be likely, it will go through the House of Lords and I hope it does go through the Human Fertilisation Embryology Authority as well. 

There is a risk of producing an abnormal baby but I think it's just like when we did in vitro fertilisation the first time, we didn't know what was going to turn out. And certainly, when we biopsied an embryo for the first time for pre-implantation diagnosis, we didn't know then whether the baby is going to be normal. We did all sorts of experiments but ultimately, the human, of course, is unique and very special.

Kat - And I'm sure the parents who've had wonderfully happy healthy children as a result of these techniques would say, "Yes, this is a really great thing to be doing."

Robert - Yes. I mean, I think that's right. I mean, I know that the women who first went into pre-implantation diagnosis, I think were immensely brave. I remember having long discussions with them because nobody has used IVF for genetic disease before. As I say, I think two things have happened, which are perhaps unwise. One is, I think that the amount of importance of this has been rather exaggerated and I think that's in fact therefore, focused too much attention on it. Secondly, I think it was very unwise to suggest that if we didn't do this first, we would leave our primacy in this area. In my view, to treat a child because you want to be first seems to me a very bad reason for doing it.

Kat - Really very briefly, what's the timeline going forward for this because this has now gone through the Commons. But this isn't suddenly, "Off we go! We're going to do this now."

Robert - No. I think you'd have lots of people in Newcastle. But I think if the HFEA give a license, I imagine they must have some patients lined up. I know that patients have been in the media, so I imagine that they will try and do this this year or next.

The vote in the House of Lords is actually on the 23rd of this month and I'm actually away. But I'm just wondering whether I should come back and speak in the debate, so I might do that.

Kat - I hope you will.

Robert - I haven't decided yet but I think probably, they'll expect me to submit breaking a very short holiday.