A ground-breaking medical development has led to eight babies being born in the UK through a fertility treatment involving the use of DNA from three people. The mitochondria donation treatment aims to stop the mother from passing on a genetic condition caused by defective mitochondria, small power stations inside our cells producing energy. These circumstances affect organs such as the brain, heart, liver, and muscles, which create a lot of disabilities or might even lead to early death.
Mitochondrial diseases are quite rare; they occur possibly once in 5,000 to 10,000 babies. About 150 children with the very serious form of this disease are born each year in the UK alone. This treatment attempts to mend the disorder by getting rid of the cause of the problem: the defective mitochondria are replaced with healthy mitochondria taken from a donor egg.
The procedure goes like this: Most of our DNA—more than 20,000 genes—lie within the nucleus of each cell and come from our mother and father. But the mitochondria have this small set of 37 genes passed from the mother only. In this new technique, the mother's nuclear DNA is put inside a donor egg that has healthy mitochondria removed of its own nuclear DNA. Now this egg is fertilized with the sperm of the father, and the resulting embryo carries DNA from three individuals: nuclear DNA from the biological parents and mitochondrial DNA from the donor.
Thus, there are indeed three genetic contributors present in the child, but the donor DNA amounts to less than 0.1% of all genetic material. It has nothing to do with traits such as looks, intelligence, or personality; rather, it makes sure the child has healthy mitochondria to energise their cells.
In recognition of its medical significance, the UK was the first country to legalise mitochondrial donation in 2015 following years of research. This highly regulated procedure is
overseen by the Human Fertilisation and Embryology Authority (HFEA), and licenses are granted only in situations where there is a high probability of transmission of mitochondrial disease. So far, less than 30 mitochondrial donation procedures have been approved in the UK, with eight confirmed successful births.