By Sanne van den Tol
On the 3rd of February, the MPs of British parliament voted in favour of the bill on the creation of “three-person babies”, which allows scientist to create babies with the DNA of the parents, but with the mitochondrial DNA of another woman, in an IVF-similar style. Naturally, the sound of “three-person babies” causes many opinions, but what exactly is a “three-person baby”?
Why is the mitochondrial DNA so important? Mitochondria are the powerhouses of cells, specifically in cells that require much energy, like muscle cells. Mitochondria, however, have their own DNA, meaning they are passed on separately from the DNA located in the nucleus, specifically, only the mother’s mitochondrial DNA is passed on. Nevertheless, mitochondrial DNA replication can still go wrong, and this is how mitochondrial diseases commence.
Mitochondrial diseases affect, as may be expected, muscles mostly, resulting in for example muscular dystrophy, but they also affect the respiratory, endocrine, cardiovascular, and nervous systems. This is why the newly developed technique offers a solution to those who cannot have children because of genital mitochondrial diseases.
The new technique, developed at Newcastle University is, as aforementioned, similar to IVF. Furthermore, it can be achieved in two ways.
Firstly is the method which has two eggs fertilized, one of the parents, with unhealthy mitochondria, and one of the donors, which has healthy mitochondria. Then the nuclei of both embryos are removed and the nucleus of the parents is placed in the egg of the donors, with the healthy mitochondria.
Secondly there is the method that occurs before fertilization, in which the nuclei of the mothers’ egg, which contains unhealthy mitochondria, and the donor’s egg are both removed. After which the nucleus of the mother is placed in the donor’s egg, which contains healthy mitochondria.
Naturally, “three-person babies” cause much controversy. For parents who have lost their children to mitochondrial disease this technique is a miracle, however, to others it seems scientists are playing God again. It is true there is some meddling with embryos, and indeed not every attempt is successful, resulting in destruction of embryos. On the other hand, there is always a risk of losing embryos, and concerning mitochondrial disease, some grow into full-grown fetuses before they die, which is harder on many a mother’s heart than an embryo which is just one cell. Concerning the DNA mix-n-matching, one does not need be worried, as the DNA of the child and its mitochondrial DNA are 100% separated. The technique solely makes sure the child also has healthy mitochondrial DNA, and its genotype is 100% of its parents. One of the concerns of parliament was that “[This] will be passed down generations, the implications of this simply cannot be predicted”, to which some scientists agreed. However, another member of parliament did notice that “This is world leading science within a highly respected regulatory regime”.
Now that the bill is approved it is passed on to the House of Lords, where it may or may not be legislated. Next to the legislation of the Bill, the HFEA (a body of the Department of Health) has to agree to license it, but this seems almost inevitable. When the bill is legislated the first attempts could take place this very same year, resulting in the first births next year.
Sanne van den Tol, class of 2016, majoring in Biomedicine, is from Halsteren, the Netherlands
