For most of us, there are specific immutable facts about life: The sun rises in the east and sets in the west. Winter leads to spring. And babies have two biological parents. But in a scientific first for the UK, scientists say they’ve successfully created a baby with DNA from three people.
The baby was born using a fertility technique called mitochondrial donation treatment (MRT). It is an attempt to prevent children from being born with devastating mitochondrial diseases caused by mutations in the cells that produce energy. The only way to prevent mitochondrial disease is to have healthy donors give a woman their egg or sperm so that the genetic mutations aren’t passed on to her child.
MRT pioneered in Newcastle, England, and allowed by law in 2015, is a variation on traditional IVF that removes the nucleus from the mother’s egg and inserts it into a donor egg and sperm. Using the resulting embryo, about 99.8% of the baby’s DNA comes from the mother and father, with a tiny bit coming from the female donor who provided her mitochondria.
According to CBS News medical contributor Dr. David Agus, scientists have been perfecting the technique to allow women carrying genes for rare fatal diseases to pass on their healthy mitochondria to their children. Last year, a baby was born in Mexico using a similar, controversial technique that involved genetic material from three people. In this case, the baby’s mother carried genes for Leigh syndrome in her mitochondria. But, by swapping them out with those from a New York-based team, she could avoid passing the mutation on to her son.
The British scientists who developed the procedure have used it in a clinical trial involving ten infertile women. The results were published in the journal Science Advances on Tuesday. The women had all undergone four rounds of traditional IVF before MRT was attempted. The scientists then added sperm and mitochondrial DNA from the women’s donors to create embryos. Finally, those embryos were implanted in the womb of each of the women.
Each woman had at least one healthy baby boy or girl born due to the procedure. The researchers plan to study the babies to see how they are doing. They’ll also be tested for signs of mitochondrial disease.
While the scientists are happy with this first success, they’re urging others to wait before using the technique. The director of Progress Educational Trust, a charity for infertility and genetic conditions, tells the BBC that this latest success “is just the first step in what will likely be a slow, cautious process of assessing and refining this form of IVF.” And that’s a good thing because it has risks. For example, the tiny amount of harmful mitochondria that can be transferred to a recipient from a donor’s egg could multiply when the embryo is implanted in the womb, which would be dangerous for the child.
