Doctors in the UK have announced the birth of eight healthy babies following a pioneering IVF procedure that uses DNA from three people. The technique, known as mitochondrial donation treatment (MDT), is designed to prevent children from inheriting incurable genetic disorders passed on through faulty mitochondria.
The four boys and four girls, including one set of identical twins, were born to seven women at high risk of passing on life-threatening mitochondrial diseases. All eight children show no signs of the conditions they were at risk of inheriting, and one further pregnancy is ongoing, according to a report published in the New England Journal of Medicine.
The procedure involves fertilising the mother's egg with the father's sperm, then transferring the nuclear genetic material into a donor egg with healthy mitochondria. This creates an embryo with the parents' chromosomes but the donor's healthy mitochondria. The UK changed the law to allow the treatment in 2015, and the first licence was granted in 2017 to a fertility clinic at Newcastle University, where doctors spent more than two decades developing the technique.
Professor Doug Turnbull, part of the Newcastle team, described the healthy births as reassuring. “You are inevitably thinking it’s great for the patients and that is a relief,” he said. Professor Mary Herbert, another senior member, said the outcome was “rewarding for all of us”.
The mother of one of the girls expressed her gratitude: “As parents, all we ever wanted was to give our child a healthy start in life. After years of uncertainty this treatment gave us hope – and then it gave us our baby … we’re overwhelmed with gratitude. Science gave us a chance.”
Genetic tests showed the babies had no or very low levels of mutant mitochondria, although a small amount carried over from the mother suggests the procedure could still be improved. All the children are meeting developmental milestones, with five under a year old, two aged between one and two, and one older child.
