Debunking for Dummies: What’s the fuss about 3-parent babies?

This instalment isn’t actually debunking. Sorry. It is about a contentious issue though

Image: Swerz

The procedure is intended to prevent mitochondrial diseases including Diabetes mellitus, deafness and some heart and liver conditions. Image: Swerz

Britain is now set to be the first country to allow genetically modified babies to be born. It’s a pretty big deal, and has been met with a large amount of opposition. But what exactly is a three-parent baby? It is an individual whose genetic make up will come from one biological father and two biological mothers. There are a few different ways to achieve this, but they all involve transplanting healthy mitochondrial DNA of one mother in place of the disease-carrying mitochondria of the nucleus-providing mother.

Most people just have a hazy memory of secondary school biology and mitochondria being something to do with the power stations of the cell. As well as fuelling everything which your body does they also contain DNA. A very small amount, but critical in cellular development. This DNA is only passed from mother to child, and thus if a mother has a condition which is passed through mitochondrial DNA the child will inherit it.

Opposition has come from religious groups, the general public, and scientists. The Catholic Church was the religious body which was most strongly opposed, which was only to be expected. The procedure involves aborting a fertilised egg. Their doctrine teaches that life begins at conception, and thus this is murder.

The Church and others also argue that by changing an unborn child at the germ line level without their consent we are giving them no choice, and no ability to return to how they were. Their DNA is permanently altered. However, much like in the case of vaccination, surely no child would choose to be born with a debilitating genetic condition?

The Archbishops’ council of the Church of England released a statement explaining how they are gravely concerned at the lack of research and consultation. Although they oppose it at the moment, it could be said that in principle they are not against the idea. That is a big step. The Church of England are not opposed to the procedure itself, just that they would like to see more testing and discussion to check that it is safe, and that it works.

There are also large groups of researches who have raised concerns with the procedure. When the technique has been trialled on rats there was a link discovered between increased rates of cancer and mitochondrial swapping. There was also evidence of an increased rate of aging and it is believed that this has something to do with the role mitochondrial DNA plays in programming cell death. For some, this is evidence enough that we do not know enough about mitochondria to be using this treatment.

In other zoological tests, over 50 per cent of trials damaged the mitochondria or caused a genetic condition arising from the transfer. Many scientists therefore argue that we need to research the method of selection and transplantation much more before it is safe to use on humans.

Image: Javcon117*

Image: Javcon117*

However, with all new technology there are worries about what will actually happen, and at some point we must move from animals to humans. Long term effects are truly unknown and this would mean that the first few cohorts of babies would have to be monitored quite closely, for their whole lives. This would allow us to check the safety and efficacy of the treatment, through reproduction and into old age. Great Ormond Street Scientists also warn that around 80 per cent of mitochondrial DNA conditions are caused by mutations in later development, and urge more effort be put in to finding a cure for that.

Three quarters of MPs to approve the change in law, implying that there must be some strong points to the contrary of the above. Primarily this law will bring an end to needless suffering. This in itself makes it a sensible decision to make. If we can prevent children being born with genetic disorders and living a disadvantaged and painful life, then why wouldn’t we? That is of course if the child is born at all. Most cases of these diseases end in a termination, miscarriage or still birth. It will allow relief from one of the most difficult decisions expecting parents can have – to have a child with the risk of it having the condition, or to abort it.

Another great thing about this treatment is the fact that it only needs to be done once per lineage. Because the germ line is altered all offspring of the individual will carry the “3rd parent” mitochondrial DNA, meaning that the conditions are prevented from being passed on to future generations.

It is also important to remember that this is not a case of three-parent families as some anti-change proponents have protested. The contribution of the donor mother is around 0.5 per cent of the total baby karyotype. This is completely separate from the nuclear DNA, which is the DNA which is responsible for your characteristics. Although it has no effect on your personality, hair colour or height, it is still terribly important when it comes to cell development. The third parent will be kept anonymous and have no rights over the child, as their contribution is negligible – approximately 27 genes.

This step needs to be taken at some point, and I for one am glad it was taken by Britain, keeping us in the lead of science policy-making, unlike many other major powers who are restricted far too much by religious pressure. At the end of the day, there will only be roughly 150 births through this technology a year, it’s not like there will be thousands of designer babies roaming the streets by December.

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