Eight babies are born with the DNA of three people in the United Kingdom

Most of the DNA is in the nucleus of our cells. Meanwhile, and it is this genetic material – inherited in part of the mother, partly of the father – who makes us who are.

But there are also DNA outside the cell nucleus, in structures called mitochondria. Meanwhile, Dangerous mutations there may cause a series of diseases that can cause muscle weakness. For example, convulsions, development delays, failure of vital organs and death in children.

Tests carried out during the in vitro fertilization process generally make it possible to detect the presence of these mutations. Meanwhile, But in rare cases, this is not easy.

The researchers developed a technique that tries to avoid this problem using the healthy mitochondria of a. Consequently, ovum from a donor. Furthermore, They announced in 2023 that the eight babies born dna three first babies were born thanks to this method. Similarly, which consists in taking genetic material from the ovum or the embryo of the mother, then transferring it to an ovum or a donor’s embryo containing healthy mitochondria, but the rest of the essential DNA was removed.

These latest research “marks an important step. Meanwhile, ” said Doctor Zev Williams, the director of Columbia University Fertility Center, who did not participate in this work. Furthermore, “Expanding the range of breeding options […] will allow more couples to carry out a safe and healthy pregnancy. ”

This method implies that the embryo has the DNA of three people: that of the mother’s egg. that of the father’s sperm and that of the donor’s mitochondria. It required a change in British legislation in 2016 to be approved. It is also authorized in Australia, but not in many other countries, eight babies born dna three including the United States.

Experts from the British University of Newcastle. the Australian University of Monash reported on Wednesday in the New England Journal of Medicine that they had applied this new technique to fertilized embryos from 22 patients, which gave birth to eight babies who seem exempt from mitochondrial diseases. A woman is still pregnant.

One of the eight babies born had levels slightly higher than normal abnormal mitochondria. said Robin Lovell-Badge, a scientist specializing in stem cells and development genetics at the Francis Crick Institute, which did not participate in research. He added that this level was not yet considered high enough to cause a disease. but that it had to be monitored as the baby’s development progresses.

Doctor Andy Greenfield. an expert in reproductive health at the University of Oxford, described this work as “triumph of scientific innovation” and eight babies born dna three declared that the method of exchange of mitochondria would only be used for a small number of women for which other means of avoiding the transmission of genetic diseases, such as the early detection of embryos, were not effective.

Mr. Lovell-Badge stressed that the quantity of DNA from the donor was insignificant. stressing that the resulting child would have no lines of the woman who would have given the healthy mitochondria. Genetic material from the given egg represents less than 1 % of the baby born after this technique.

“If you have undergone a bone marrow transplant from a donor. you will have many more DNA from another person,” he said.

In the United Kingdom. all couples wishing to have a child born through a donation of mitochondria must be approved by the country’s fertility regulatory authority. To date, 35 patients have eight babies born dna three been allowed to use this technique.

The detractors have already expressed their concerns. warning that it is impossible to know the impact that this type of innovative techniques could have on future generations.

In countries where this technique is authorized, its defenders claim that it could constitute a promising alternative to certain families.