In a groundbreaking medical achievement, eight babies have been born in the UK using genetic material from three individuals to prevent the transmission of fatal mitochondrial diseases.
This pioneering fertility technique, developed by scientists at Newcastle University, is now being hailed as a world first in clinical success.
The children, born through a process that combines the egg and sperm of the parents with mitochondrial DNA from a donor woman, show no signs of mitochondrial disease—a debilitating condition that affects energy production in cells and can lead to brain damage, muscle failure, and death in infants.
The technique, legalised in the UK in 2015 after parliamentary approval, was designed to help families with a known risk of passing on defective mitochondria. Mitochondria, which contain their own DNA, are passed exclusively from mother to child.
By replacing the mother’s damaged mitochondria with healthy ones from a donor, doctors are able to prevent transmission of the disease.
The Newcastle Fertility Centre, which performed all the procedures, reported that the eight babies—four boys, four girls including a set of twins—are all meeting normal developmental milestones.
One child experienced epilepsy that later resolved on its own, and another is receiving treatment for an abnormal heart rhythm, though neither issue is believed to be linked to mitochondrial defects.
Parents of the children, speaking anonymously through the clinic, expressed immense gratitude. “After years of uncertainty this treatment gave us hope—and then it gave us our baby,” said one mother. Another said the emotional weight of mitochondrial disease had been replaced by “hope, joy, and deep gratitude.”
Around one in 5,000 babies in the UK are affected by mitochondrial disorders, and some parents have experienced the tragedy of losing more than one child. The new technique brings fresh hope to families like the Kittos, whose daughter Poppy lives with the disease and whose elder daughter Lily could one day pass it on.
While the UK has led the way in both scientific research and legal regulation of mitochondrial donation, experts stress the need for continued study. Questions remain about why some low levels of defective mitochondria persisted in a few children, although these were well below disease-causing thresholds.
Professor Bobby McFarland, director of the NHS service overseeing mitochondrial treatment, called the results “brilliant,” while Prof Doug Turnbull praised the unique combination of UK science, legislation, and healthcare support that made this medical milestone possible.
“This is the first real hope of breaking the cycle,” said Liz Curtis, founder of the Lily Foundation charity.
