Mitochondrial diseases are thankfully rare, but that’s not much consolation for the hundreds of families whose children suffer severe and debilitating ill health as a result of inheriting defective genes from their mothers.
Mitochondrial DNA is not like the nuclear DNA of the chromosomes. It exists outside chromosomes of the nucleus and is passed down the generations through the maternal line – we all have our mothers’ mitochondrial DNA.
A technique known as mitochondrial donation, where the healthy mitochondria of a donor egg or embryo are used in IVF treatment, therefore promises to provide affected women with a way of having children who are free of the condition.
The fact that Britain is on the verge of becoming the first country in the world to permit this treatment in law should therefore be applauded as a progressive act that could enhance the lives of many families – provided the technique is shown to be safe.
However, there should be no qualms about what this involves. For the first time, we will be allowing scientists to alter the DNA of future generations, so-called germ-line modification, by bringing together the genetic material of three people into one embryo.
By any stretch of scientific definitions, this amounts to genetic modification (GM), and no amount of dissembling by the Government changes that fact. It is quite wrong, therefore, for the Department of Health to come up with a “working definition” of GM that conveniently excludes mitochondrial donation.
GM should not be the scientific term that dare not speak its name. There is nothing inherently wrong with it, just as there is nothing inherently wrong with “nuclear magnetic resonance imaging” – except that someone in officialdom decided that “nuclear” was too risqué to be included in the description of a hospital MRI scanner.