What should we make of the recent government decision to allow babies to be born who are genetically related to three individuals?
Is it a step closer to the “brave new world” imagined by writer Aldous Huxley, or are things more complex?
Certainly the term “three parent baby” is misleading.
It suggests that a child may get its genetic inheritance equally from three people, which is not the case.
Instead it’s an approach to help families with so-called “mitochondrial gene disorders”, a condition that affects one in 6,500 people.
Mitochondria are tiny power stations within our cells that supply the bulk of their energy needs.
In contrast to the 99.9 percent of our DNA genome within the nucleus of our cells, mitochondria possess their own genomes.
This is because mitochondria were originally free-living bacteria.
They became incorporated into the more complex cells that now make up our bodies around two billion years ago.
The poison cyanide shows just how important mitochondria are for life.
It stops them producing energy and leads to immediate death.
And people with mutations in their mitochondrial DNA suffer from seriously debilitating disorders of the muscles, heart or brain.
The “three parent” approach is designed to help people with mitochondrial gene disorders who don’t want to pass the condition on to their children.
We inherit our mitochondria only through our mothers as they are only passed down the generations through the egg, not the sperm.
The nucleus from the egg of a woman with a mitochondrial gene disorder can be transplanted into a donor egg from another woman with its own nucleus removed.
If this egg is fertilised with a sperm from the first woman’s partner, it should be possible for her to have an unaffected child.
It is true that the child will inherit their mitochondrial DNA from the third individual. But this represents just 0.1 percent of our total genome, or hereditary information. And it only codes for the proteins involved in cellular energy production, not for those that affect our appearance or personality.
So it’s hard to see how this makes the third individual a parent in any normal sense, although clearly there are ethical implications that need wider discussion.
A key issue for me is whether this approach is safe. Increasingly, children are being born through some highly invasive procedures.
A sperm is sometimes injected into an egg through a glass needle if it can’t penetrate the egg normally, to treat certain types of infertility.
In another common procedure, a cell may be removed from an eight-cell embryo to test if any embryo is carrying a genetic disease like cystic fibrosis.
Remarkably, children born using these approaches appear completely normal.
But there are concerns that not enough research is being carried out to investigate the possibility of health problems in later life. This is both in terms of proper screening of people born using new reproductive technologies, and through studies in animals.
Socialists should put two key demands.
First, revolutionary new technologies to treat infertility and genetic disease ought to be freely available on the NHS.
And second that there is proper investigation into the long-term safety of such approaches.