How close are we to customising babies?

From joy and attachment to anxiety and protectiveness, mothering behavior begins with biochemical reactions. (Getty/AFP)

The Food and Drug Administration in the United States is holding meetings this week to look into a controversial fertility treatment that would combine the genetic material of three people in order to avoid passing on certain genetic defects.

Critics are speaking out against the treatment, saying it will create "designer babies" while some members of the scientific community praise the treatment for creating the possibility of eliminating the possibility of inheriting a severe disability.

Romi Levine spoke to Dr Martin Delatycki, a clinical geneticist working with the Human Genetics Society of Australia.

Can you explain the science behind the procedure?

Basically, a cell contains a nucleus and most of the genes that make us who we are are in the nucleus. There are about 23,000 pairs of genes there. And then in the rest of the cell there are numerous structures and amongst those are structures called mitochondria. Mitochondria are like batteries to the cell – they provide energy to the cell but also they contain 37 genes and so there’s one nucleus with a pair of each of the genes but in the mitochondria there’s thousands of mitochondria in a cell.

If there is a mutation or a fault in the mitochondrial genes, then this is present in a percentage of those many thousand mitochondria. All our mitochondria are inherited from our mother. We don’t inherit mitochondria from our father because the mitochondria in the sperm are in the head of the sperm and it’s only the head of the sperm that fertilises the egg. So if there is a genetic mutation of the mitochondria, that’s inherited through the mother and not the father.

So the rationale for this process is that if you want to have a child that is genetically pretty much from you as a woman but you have faulty mitochondrial genes, then you can, in simplistic terms, put your nucleus in another woman’s egg and so that your offspring inherit the 23,000 genes in the nucleus from you and the 37 genes in the mitochondria from another person who doesn’t have faulty mitochondrial genes. That child will be in always your genetic progeny but their mitochondria will not be from you so they won’t be at risk of these conditions.

The sort of conditions that can occur can be very devastating conditions with shortened life span, mental retardation, heart damage, diabetes, deafness. There’s a whole range of problems that can be very very significant.

We don’t know what might happen – what the interactions are between the nucleus and the rest of the cell so there’s concerns that this might cause other problems that no one has thought through that no one understands. So the people who are against this, particularly ethicists, say there are other ways around this by using donor eggs that are complete so that you can still have a child but it won’t be genetically related to the mother or donor embryos that have finished IVF (In vitro fertilisation) or something like that.

The people who are keen on advancing this in humans say they’ve done lots of studies in animals and particular in non-human primates and haven’t found increased rates of problems and they say well, when we started IVF we didn’t really know what we were getting ourselves into and at some point we had to bite the bullet and say let’s give this a go and see what happens. And so those people feel that as a society we’re ready to move into doing this for couples where they’re fully informed about the pros and cons and understand that there may be risks that haven’t been discovered yet.

Where do you stand in all of this? Do you think that it is a matter of playing god or is it time to move forward?

This was first done about 15 years ago and some children have been born from this sort of process and have been healthy to this point, although they’re obviously not reaching adulthood so later on problems haven’t been completely excluded.

I think at some point, once the scientific community and ethicists who sit on panels look at this and agree as much animal data is available as is possible and there’s no obvious problems, then I think at that point, it is reasonable for a family to have this option, understanding that there may be things that haven’t been foreseen.

So, for example, there are rare complications of IVF, rare problems that are more common in children born with IVF that are now only becoming apparent 30 years after it was first carried out. So at some point, if it’s going to be done, someone is going to have to bite the bullet and do it. But it needs to be done in an open and in a way that families know that there are risks and the outcomes are very carefully studied so that if it comes apparent that it is causing problems then it should be ceased at that point.

Would this FDA approval mean that the procedure can be used on humans?

So if the FDA approves it, they’re kind of the body in the US who have to give permission for things like the use of new medications for new surgical procedures and techniques, and this is another example where they would be required to provide approval before it’s legal in the US for a hospital to offer this procedure to couples.

Are there similar genetic procedures that are being tested out in Australia?

To the best of my knowledge the answer is no. These are not available in Australia. The technical ability to do it is certainly present. People will be aware that Australia has always been at the forefront of IVF research.

What’s the ethical climate here in Australia compared to somewhere like the US? Are people more open to this kind of customised fertility treatment?

I think that in general we tend to follow the lead and so if other major countries forbid something like this it’s likely that it wouldn’t go ahead in Australia but once it’s approved in bigger jurisdictions in Europe and in the US, we would tend to take it up at that point. But there have certainly been – in the early days of IVF, as I say, Australia were leaders in many of the techniques that are common place. Australia was the first country to do many of these. 

The futuristic concept of creating a baby and customising the features of the baby – for example saying ‘I want a baby with blue eyes and blonde hair’ – is this something that’s conceivable?

So the answer is – certainly not possible now. But what you’re talking about is often referred to as the slippery slope. So if we allow this now for avoiding a genetic condition – in this case, genetic conditions that are due to the mitochondrial DNA, then can we use the same technology to choose for characteristics than to prevent what most people would consider disabilities - so a taller child, a more intelligent child with certain appearance characteristics. And the answer is at the moment, this is simply not feasible or possible. Genetics is moving forward at an incredible pace so these things will become more and more possible and clearly the thing that society needs to do is to decide what is acceptable and prescribe against things that are unacceptable and I think there will be a lot of objection to selecting for things such as height and hair colour. But there is pretty wide acceptance and positivity around the ability for couples to avoid having a child with a sever disability for example.

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