News that should make you proud to be British: we’re going to become the first nation to get over our it-ain’t-natural squeamishness and offer the new form of IVF treatment that will allow children to be born with “three parents”.
The inexplicably controversial treatment involves using the mitochondrial DNA of a donor, with the usual chromosomal DNA from a mother and father.
Chromosomal DNA is the DNA you normally think of, the stuff that gives you blue eyes or ginger hair, or decides whether you’re a boy or a girl, which is in the nucleus, the sort of central processing centre, of our cells. You get half your chromosomal DNA from your mum, and half from your dad. The mitochondrial DNA is entirely separate; the mitochondria are tiny former bacteria which live in your cells and act as the “batteries” or “power stations” of the body, converting food into usable chemical energy. The mitochondria in sperm aren’t involved in fertilisation, so you only get them passed down from your mum.
The amount of information in mitochondrial DNA is minuscule compared to the chromosomes. There are 37 genes in mitochondrial DNA, compared to around 20,000 in the nucleus, and they don’t have direct effects on how the body grows: your skin tone, hair colour etc are all dictated by the chromosomes (and environmental factors). But when mitochondrial DNA goes wrong, it can be devastating: it can cause nervous and muscle diseases, like Parkinson’s, or multiple sclerosis-type disorders, among dozens of others. A mother who has a genetic mitochondrial disorder will pass it on to her children, so it makes sense to replace the defective mitochondria with healthy ones. That’s done by taking the chromosomes from the mum and putting them into the nucleus of an egg cell from a healthy donor, which has had its own chromosomes removed: a technique pioneered by a British scientist, Doug Turnbull, at the University of Newcastle.
Calling this process “making children with three parents” is stretching the point somewhat: nothing about the child will be like the “third” parent except their freedom from certain diseases (and their efficiency at processing chemical energy, which I suppose isn’t nothing). We don’t need to start worrying about three-way custody battles or anything, it’s just a way of allowing parents to have healthy children.
And it’s fantastic that the British government has become the first in the world that will allow this process (the first baby could be born the year after next, apparently). We’re too often afraid of “playing God” and things that “aren’t natural”, and, like Jehovah’s Witnesses refusing blood transfusions, we let these vague fears stop us from improving humanity’s lot. The Coalition deserves credit for pushing this through.