In a major medical breakthrough, scientists in the UK have helped parents at risk of passing on serious inherited diseases have healthy children. By using a special technique called mitochondrial donation, the team has successfully created eight babies who are now living without the genetic disorders that have affected generations in their families.
The procedure, which uses DNA from three people, was carried out by researchers from Newcastle University. The results of their work were recently published in The New England Journal of Medicine.
The children, four boys and four girls, including a pair of identical twins, are now between a few months and over two years old. So far, all appear to be healthy and are growing normally.
Why was this needed?
The families involved were at high risk of passing on rare but deadly mitochondrial diseases. These conditions are caused by faulty mitochondria, tiny parts inside our cells that act like power plants, giving our cells energy to function.
When mitochondria don’t work properly, they can cause a wide range of serious problems like heart failure, strokes, brain damage, blindness, and muscle weakness. In many cases, children born with mitochondrial disorders don’t live long and may suffer a lot during their short lives.
These diseases are passed only from mother to child through a small part of DNA found in mitochondria. So, if a mother has defective mitochondrial DNA, there’s a high chance she could pass it on to her baby.
How does the technique work?
The method used by the UK scientists is called pronuclear transfer, which is one form of mitochondrial donation. It works by taking the healthy nuclear DNA from a fertilised egg created by the parents and placing it into a donor egg. The donor egg has healthy mitochondria but has had its own nuclear DNA removed.
This means the resulting embryo contains:
- Nuclear DNA from the mother and father (which determines things like physical traits and personality)
- Mitochondrial DNA from the donor (which provides healthy cell energy)
In total, the baby ends up with DNA from three people, but the donor’s contribution is very small, around 0.1 per cent of the baby’s total DNA. That’s why these children are sometimes called “three-parent babies.”
How can this technique change lives?
Dr. Doug Turnbull, professor of neurology at Newcastle University and one of the lead researchers on the project, said this technique could change lives.
“Mitochondrial disease can be devastating for the family. It can be tragic,” he said. “This is an important breakthrough, a big step forward.”
The goal, scientists say, is simple: to give parents who carry these dangerous mutations the chance to have a healthy, genetically related child without the fear of passing on a life-threatening disease.
Robin Lovell-Badge, a developmental biologist at the Francis Crick Institute in London, echoed that sentiment.
“Watching your child suffer and slowly die from one of these conditions is truly heartbreaking,” he said. “This research offers real hope for those families.”
According to the study, the babies are doing well so far. But researchers say long-term monitoring is essential to ensure the procedure is safe.
Ethical concerns and safety worries
Some scientists and ethicists have raised concerns about what this could mean in the long run.
One worry is that changes to mitochondrial DNA, although small, can be passed down through generations. If something were to go wrong, it could affect not just one baby, but their children and grandchildren.
Some fear this could be the first step toward genetic manipulation to create “designer babies,” children whose genes are chosen to control things like intelligence, appearance, or talent.
Dr. Stuart Newman, professor of cell biology at New York Medical College, expressed concern:
“It’s biologically dangerous. And it’s dangerous culturally because it opens the door to manipulating genes, not just to prevent disease, but possibly to select traits,” he said.
Francois Baylis, a Canadian bioethicist, also raised questions about the risks involved for both the women donating their eggs and the women receiving the embryos.
“We don’t know all the risks, especially long-term ones,” she said. “There’s also this idea that your own genes are the only ones worth passing on. That mindset should be questioned.”
Baylis added that there are other options for parents, like adoption or using donor eggs entirely, that don’t involve genetic manipulation.
Is this gene editing?
One common misunderstanding is that this is the same as gene editing or using tools like CRISPR. But scientists stress that mitochondrial donation does not involve editing genes. Instead, it’s a method to avoid faulty genes being passed on.
Dr. Lovell-Badge explained: “This is totally different. We’re not changing genes, we’re replacing damaged mitochondria. The goal is to prevent serious disease, not to change what a child will look like or how they’ll behave.”
Is it allowed everywhere?
Right now, the UK is one of the only countries that allows mitochondrial donation under strict medical regulations. Australia has also legalised it. In the US, the procedure is banned for use in making babies, although one doctor did perform the treatment in Mexico in 2016 for a Jordanian couple.
Clinics in countries like Greece and Ukraine have also offered similar procedures, mainly to help with infertility, but experts say it’s unclear how effective or safe that is for those purposes.
Dr. Turnbull believes strict oversight is essential to prevent misuse. “I think there are enough checks and balances in the system to stop this from becoming a slippery slope to designer babies,” he said.
What’s next?
Researchers say the early results are very promising, but the technology is still in its early stages. Long-term monitoring of the children is needed to confirm the method is truly safe over time.
For now, this breakthrough offers a ray of hope to many families living in fear of passing on deadly diseases. “We now have a real option for these families,” said Turnbull. “That’s something to celebrate.”
