British MPs have voted to allow IVF (in-vitro fertilisation) babies to be created that have genetic material from three adults instead of two. The amendment to the 2008 Human Fertilisation and Embryology Act means that women can donate their mitochondrial DNA to others who are at risk of passing on mitochondrial disease to their children.
Mitochondrial genes are often referred to as the battery of human cells, because they provide energy rather than contributing to a person’s appearance. They are only passed down through the maternal line and account for just 0.054% of a person’s DNA, but mitochondrial disease can be devastating. The new amendment means that scientists can now use two eggs during the IVF process, one from the prospective mother and one from a donor. The nucleus (the part of the cell that carries most of the DNA) will be removed from the donor egg, and replaced with the nucleus from the mother’s egg. This will leave the donor’s mitochondrial genes intact and ensure that the mother’s mutated mitochondrial genes aren’t passed on to her child. 99.8% of the infant’s DNA will be from the parents, with just 0.2% coming from the donor.
Of course, as with most advances in IVF there have been objections. These range from religious reasons to those concerned whether the donor would or should have any legal rights in regard to the child. There are also those who are concerned about the ethics of the process, with some likening it to eugenics or the creation of so-called “designer babies”.
The new amendment will now have to be approved in the House of Lords but it’s expected to pass, meaning that mothers now have the hope of bearing a child who is free of mitochondrial disease.