Latest news with #mitochondrial DNA
Fox News
6 days ago
- Health
- Fox News
Three-person IVF technique shown to prevent inherited genetic diseases
An unconventional approach to reproduction is reportedly reducing the risk of metabolic disease. Three-person in vitro fertilization (IVF), a new concept developed by scientists in New Castle, U.K., has resulted in the births of eight healthy children. In the study, published in The New England Journal of Medicine, the researchers found that pathogenic variants in mitochondrial DNA (mtDNA) are a "common cause" of severe — and often fatal — inherited metabolic disease. This DNA in the mother's mitochondria can cause "harmful mutations" in children, which can lead to diseases that affect tissues in the heart, brain and muscles, according to the journal Nature. At the Newcastle Fertility Centre, 22 women with pathogenic mtDNA variants underwent a "pronuclear transfer," in which they received a mitochondrial donation. This involved the transfer of the nucleus of a fertilized egg with "faulty mitochondria" into a donor egg cell with healthy mitochondria, Nature detailed. The result includes nuclear DNA from both the biological mother and father, as well as mitochondrial DNA from the separate egg donor. From this, eight children were born healthy, with no levels or low levels of mtDNA detected in their blood. The researchers noted that one child did develop hyperlipidemia (high cholesterol) and cardiac arrhythmia (irregular heartbeat) — as the child's mother had hyperlipidemia during pregnancy — but both conditions responded to treatment. Another child developed infant myoclonic epilepsy — a rare type of epilepsy that typically affects infants between 6 months and 3 years old — which concluded in "spontaneous remission." "At the time of this report, all the children have made normal developmental progress," the researchers noted. Dr. Zev Williams, director of Columbia University Fertility Center in New York City, said this latest research "marks an important milestone." "Expanding the range of reproductive options … will empower more couples to pursue safe and healthy pregnancies," he said in an interview with Fox News Digital. In a press briefing, Robert McFarland, a pediatric neurologist at Newcastle University, who co-led one of the studies, reportedly noted the team's "cautious optimism" about the results. "To see babies born at the end of this is amazing, and to know there's not going to be mitochondrial disease at the end of that," he said. Fox News Digital reached out to the study researchers for comment.
Gizmodo
17-07-2025
- Health
- Gizmodo
8 Healthy ‘Three-Parent' Babies Born in UK Using Pioneering IVF Technique
So-called 'three-parent' babies are thriving in the U.K. New clinical trial research shows that several healthy children in the country have been born with the DNA of three people. Doctors at Newcastle University led the study, which involved around two dozen women with a high risk of passing down harmful mutations of their mitochondria to their children. So far, eight kids have been born using an in vitro fertilization (IVF) technique that replaces a mother's damaged mitochondrial DNA with that of a donor, all of whom appear to be disease-free. The findings seem to validate this new approach to preventing these genetic disorders. 'As parents, all we ever wanted was to give our child a healthy start in life. Mitochondrial donation IVF made that possible,' said the mother of a girl born with the method in a statement from the university. 'After years of uncertainty, this treatment gave us hope—and then it gave us our baby. We look at them now, full of life and possibility, and we're overwhelmed with gratitude. Science gave us a chance.' Mitochondria are the cell's primary source of energy, but only a tiny slice of our genetic material is responsible for creating them. This mitochondrial DNA (mtDNA) is found outside the nucleus, unlike the rest of our DNA, and the genes for making mitochondria are only inherited from our mothers. Certain mutations of mtDNA are known to cause serious diseases, and women whose eggs carry these variants can pass them down to their children. The technique pioneered by Newcastle researchers sought to get around this risk in a relatively simple way. They use standard IVF to create a fertilized egg with the mother's and father's DNA, then remove the nucleus. This nucleus is inserted into a donor egg that had its nucleus removed, which is finally transplanted into the mother's uterus for a hopefully successful pregnancy. If all goes well, the resulting child carries all the nuclear DNA of their parents and the healthy mtDNA of the donor. The researchers enrolled 22 women carrying harmful mtDNA variants to undergo the IVF procedure. These women were compared to a group of women who instead received preimplantation genetic testing (PGT), a common screening technique that can select for healthy mitochondria prior to IVF (for some women, a harmful mtDNA variant will only show up occasionally in their eggs). Eight women who underwent mitochondrial donation had live births, while another woman has an ongoing pregnancy. None of the children—four boys, four girls, and a set of identical twins—have shown signs of mitochondrial disease so far, and all are reaching their developmental goals on schedule. The success rate of the technique (36%) was also similar to PGT (41%). The results were published across two studies in the New England Journal of Medicine. The findings do point to some current limitations of mitochondrial donation. Some of the children had mitochondria carrying harmful mutations, for instance. Even in these children, however, most of their cells still carried healthy mitochondria, and their levels of mutated mitochondria are likely low enough to prevent disease from emerging. But this result will merit further monitoring of the children, and it suggests the IVF method can be improved to lessen the chance of it happening. Earlier versions of mitochondrial donation have been developed, though these were eventually banned in countries like the U.S. for being too dangerous. The UK has slowly but steadily been laying the groundwork for this newer and safer technique to be cleared for widespread use (the country officially allowed the first treatment in 2018, now seven years ago). So while there may be important questions left to answer, many women living with this genetic risk may soon have a new option available that will allow them to have children of their own.
CNA
17-07-2025
- Health
- CNA
Three-person IVF technique spared children from inherited diseases, scientists say
Eight children in the UK have been spared from devastating genetic diseases thanks to a new three-person in vitro fertilization technique, scientists from Newcastle University reported on Wednesday. The technique, which is banned in the United States, transfers pieces from inside the mother's fertilized egg - its nucleus, plus the nucleus of the father's sperm - into a healthy egg provided by an anonymous donor. The procedure prevents the transfer of mutated genes from inside the mother's mitochondria - the cells' energy factories - that could cause incurable and potentially fatal disorders. Mutations in mitochondrial DNA can affect multiple organs, particularly those that require high energy, such as the brain, liver, heart, muscles and kidneys. One of the eight children is now 2 years old, two are between ages 1 and 2, and five are infants. All were healthy at birth, with blood tests showing no or low levels of mitochondrial gene mutations, the scientists reported in the New England Journal of Medicine. All have made normal developmental progress, they said. The results "are the culmination of decades of work," not just on the scientific/technical challenges but also in ethical inquiry, public and patient engagement, law-making, drafting and execution of regulations, and establishing a system for monitoring and caring for the mothers and infants, reproductive medicine specialist Dr. Andy Greenfield of the University of Oxford, who was not involved in the research, said in a statement. The researchers' "treasure trove of data" is likely to be the starting point of new avenues of investigation, Greenfield said. Often during IVF screening procedures, doctors can identify some low-risk eggs with very few mitochondrial gene mutations that are suitable for implantation. But sometimes all of the eggs' mitochondrial DNA carries mutations. In those cases, using the new technique, the UK doctors first fertilize the mother's egg with the father's sperm. Then they remove the fertilized egg's 'pronuclei' – that is, the nuclei of the egg and the sperm, which carry the DNA instructions from both parents for the baby's development, survival and reproduction. Next, they transfer the egg and sperm nuclei into a donated fertilized egg that has had its pronuclei removed. The donor egg will now begin to divide and develop with its healthy mitochondria and the nuclear DNA from the mother's egg and the father's sperm. This process, detailed in a second paper in the journal, 'essentially replaces the faulty mitochondrial DNA (mtDNA) with healthy mtDNA from the donor,' senior researcher Mary Herbert, professor of reproductive biology at Newcastle, said at a press briefing. Blood levels of mtDNA mutations were 95 per cent to 100 per cent lower in six newborns, and 77 per cent to 88 per cent lower in two others, compared to levels of the same variants in their mothers, the researchers reported in a second paper. "These data indicate that pronuclear transfer was effective in reducing transmission of mtDNA disease," they said. The procedure was tested in 22 women whose babies were likely to inherit such genes. In addition to the eight women who delivered the children described in this report, another one of the 22 is currently pregnant. Seven of the eight pregnancies were uneventful; in one case, a pregnant woman had blood tests showing high lipid levels. There have been no miscarriages. The authors of the current reports have also tried transplanting the nucleus of a mother's unfertilized egg into a donor egg and then fertilizing the donor egg afterward, but they believe their new approach may more reliably prevent transmission of the genetic disorders. In 2015, the UK became the first country in the world to legalize research into mitochondrial donation treatment in humans. That same year in the United States, pronuclear transfer was effectively banned for human use by a congressional appropriations bill that prohibited the Food and Drug Administration from using funds to consider the use of "heritable genetic modification".
Telegraph
16-07-2025
- Health
- Telegraph
First ‘three-parent' babies found healthy in scientific breakthrough
Eight healthy babies with the DNA of three people have been born in Britain in a groundbreaking first hailed as a 'scientific tour-de-force.' Dubbed 'three parent babies', the infants carry the genetic material of a 'second mother' to repair damage in their mitochondrial DNA, which powers the cells. British scientists have spent decades perfecting the technique, which involves transplanting nuclear DNA – containing all the characteristics of a person – into a donor egg with healthy mitochondria. Scientists hope the breakthrough can help women whose children would be at risk of mitochondrial disease. Every year around one in 5,000 children are born with mitochondrial mutations in Britain, while 12,000 are living with a mitochondrial disorder. These can lead to serious problems such as heart and liver failure, blindness, deafness, diabetes, respiratory problems and even death. After following the infants for up to two years, scientists announced on Wednesday that the technique works and all the babies are healthy. Professor Sir Doug Turnbull, Emeritus Professor of Neurology, at Newcastle University, who led the team said: 'I think everybody knows I'm a natural pessimist, so it's a relief. 'Mitochondrial disease can have a devastating impact on families. Today's news offers fresh hope to many more women at risk of passing on this condition who now have the chance to have children growing up without this terrible disease.' The disease is passed down solely from the mother, and there is no cure, but in the late 1990s, scientists began to question whether the defective mitochondria could be replaced with healthy donor DNA. While nuclear DNA is the blueprint for the entire cell, comprising around 3.3 billion base pairs, mitochondrial DNA only codes for energy production and is built from around 16,000 base pairs. Nevertheless, the idea proved controversial, with both the Church of England and the Catholic Church in England and Wales questioning whether the technique was safe or ethical. Experts from the Zoological Society of London warned that in 50 per cent of animal studies, faulty mitochondrial DNA had been transferred over during the procedure, while the US Food and Drug Administration deemed the process unsafe. In spite of the objections, Parliament approved new legislation to allow the procedure in 2015, and the first licence was granted in 2017 to Newcastle Fertility Centre, which pioneered the technique. The procedure involves transplanting the nuclear DNA - which contains all the genes that make up individual characteristics –from a fertilised egg to an egg donated by an unaffected woman which has had its nuclear DNA removed. The resulting embryo inherits its parents' nuclear DNA, but the mitochondrial DNA is inherited predominantly from the donated egg. Early attempts failed and it was not until 2023 that Freedom of Information requests showed the first baby had been born in Newcastle by these methods. At the time, researchers were reluctant to discuss the case, leading to fears the child had not survived. Now, two years on, scientists say the infant is growing well and has passed all developmental milestones. Seven other children have also been born through the process without any major complications, and all eight babies show no signs of having mitochondrial DNA disease. Prof Bobby McFarlane, Professor of Paediatric Mitochondrial Medicine at Newcastle University said: 'All the children are well and they are continuing to meet their developmental milestones. 'While longer term follow-up of children born following mitochondrial donation is of paramount importance, these early results are very encouraging. 'Seeing the joy and relief these children have brought to their parents is such a privilege.' Life and possibility The parents did not want to be named but said they were 'overwhelmed with gratitude', and thankful to the scientists who allowed them to conceive healthy children. One mother of a baby girl born following mitochondrial donation said: ' After years of uncertainty this treatment gave us hope –and then it gave us our baby. 'We look at them now, full of life and possibility, and we're overwhelmed with gratitude. Science gave us a chance.' The mother of a baby boy added: 'This breakthrough has lifted the heavy cloud of fear that once loomed over us. Our little family is complete.' Scientists hope the breakthrough can help around 150 women a year. Unlike with egg or sperm donors, children are not entitled to know the details of their mitochondrial donor unless they have agreed to share the information. However in some cases friends or family members have donated their DNA. Commenting on the research Dusko Ilic, Professor of Stem Cell Science, King's College London, said the healthy births were 'a remarkable accomplishment'. Dr Andy Greenfield, Honorary Fellow at the Nuffield Department of Women's & Reproductive Health at the University of Oxford, added: 'It is a triumph of scientific innovation in the IVF clinic – a world-first that shows that the UK is an excellent environment in which to push boundaries in IVF. A baby was born in 2016 in Mexico using a similar technique developed by British researchers, but it is not known if the child survived.
