Last month newspapers reported widely on the legalisation of “three-parents” babies in the UK.
The new form of treatment won a majority vote in the British House of Commons.
The new procedure prevents mitochondrial genetic diseases from being passed on by parents to their children. The process consists of using the egg of a woman who wants to have children but is the carrier of a genetic disease, the healthy sperm of either the woman’s partner or a sperm donor, and also another young healthy donor’s egg.
The whole process is conducted in an embryology lab.
First the embryos are created. Both the future mother and the donor’s eggs are fertilised with the partner or donor’s sperm. Once the embryos have been created, the nuclei -containing the highest amount of DNA- are separated from the cytoplasm, which usually contains the triggers for a range of genetic diseases. Therefore, the recipient’s nucleus is used together with the egg donor’s healthy cytoplasm. The gamete is then transferred to the recipient and future mother’s womb.
Transmitting mitochondrial diseases can be prevented with this procedure. Typically, these types of diseases lead to brain damage, heart failure and blindness, often resulting in babies unable to survive their first year of life. Transmission can only be stopped by using this technique in the early stages of conception and, consequently, in vitro fertilisation is essential.
As well as preventing mitochondrial diseases from being transmitted, this technique enables a high percentage of DNA to be used from both parents. The egg donor only contributes 0.18% of the full DNA, minimally affecting the baby’s genetic features.
As with all advances of this kind, the breakthrough has raised considerable controversy in the field of bioethics. However, the scientific community defends this procedure solely and exclusively for the benefits derived by the affected party.