A brief history of “three-parent babies”

We heard this week that eight children were born in the United Kingdom after an experimental form of artificial insemination that includes the DNA of three people. The approach was used to prevent women with genetic mutations from passing mitochondria diseases to their children. You can read everything about the results, and receive them, here.

But these eight children are not the first “three masters” children there. Over the past decade, many teams use differences in this approach to help people have children. This week, let’s look at last Children who were born from three people from artificial insemination.

I can’t go forward without talking about the term we use to describe these children. Journalists, including me, called them “three -time children” because they were created using DNA of three people. In short, the approach usually includes the use of DNA from the nucleus of egg cells and intended sperm. This is where most DNA is located in the cell.

But it also uses the DNA of mitochondria (MTDNA)-the DNA acid in energy-producing the cell-from a third person. The idea is to avoid using mtdna from the intended mother, perhaps because it carries genetic mutations. The other teams did this in the hope of treating infertility.

MTDNA, which is usually inherited from the person’s mother, is a small part of the overall inherited DNA. It includes only 37 genes, and it is believed that all of them play a role in how mitochondria works (unlike, for example, eye color or height).

For this reason, some scientists despise the term “three -father child”. Yes, the DNA has three people, but these three cannot be seen ParentsCritics argue. For the sake of the medium, this time I will use the term “IVF from three people” from here on.

Therefore, for these children. The first was reported again in the 1990s. Jack Cohen, then at the St. Paranches Medical Center in Levingstone, New Jersey, and his colleagues that they may be able to treat some cases of infertility by injecting cytoplasm containing mitochondria from proper eggs in eggs from the intended mother. Seventeen children were eventually born in this way, according to the team. (Side note: In their paper, the authors describe children caused by “three individuals”.)

But it seems that two embryos have genetic deformities. One of the children began to show signs of growth disorder. In 2002, the US food and Drug Administration developed a cessation of research.

Children born during that study in their twenties now. But scientists still do not know why they saw these distortions. Some believe that mixing mtdna of two people may be a problem.

The latest methods of three people from three people aim to include MTDNA from the donor only, completely transgressing MTDNA for the intended mother. John Chang at the New York City Center tried this approach to Jordan’s couple in 2016. Women carried genes for deadly mitochondria and have already lost two children on it. She wanted to avoid transferring him to another child.

Zhang took the nucleus of a woman’s egg and entered it into a donor egg that has been removed for her special nucleus-but she still has cytoplasm containing mitochondria. Then this egg was fertilized with the sperm of the woman’s husband.

Because it was still illegal in the United States, Zhang controversially performed the procedure in Mexico, Where, as he told me at that time, “there are no rules.” The couple eventually welcomed a healthy girl. Less than 1 % of the boy’s mitochondria boiled his mother’s boom, so the procedure was considered success.

There was little anger at the scientific community. Mitochondria was donated to the UK in the previous year, but no clinic was granted a license to do so. Zhang’s experience appears to have been conducted without observation. Many wondered about his ethics, although Sian Harding, who reviewed the ethics of the UK procedure, told me that he was “good or better than we will do in the United Kingdom.”

The scandal barely faded at a time when the children coming from the “three artificial insemination” were announced. In 2017, a team at the Nadiya Clinic in Ukraine announced the birth of a young girl for parents who have suffered from infertility treatment. The news brought more anger from some circles, and scientists have argued that the experimental procedure should be used only to prevent acute mitochondria diseases.

It was not until that year that the UK fertility authority granted a team in Newcastle a license to perform a mitochondria donation. This team launched an experiment in 2017. The big news – the first “official” experience to test whether the approach could safely prevent mitochondria.

But it was slow. Meanwhile, the other teams were making progress. Nadia clinic continued to experience the procedure in infertility couples. Pavlu Mazur, the former embryos scientist who worked in that clinic, tells me that 10 children were born there as a result of donating mitochondria.

Mazur then moved to another clinic in Ukraine, where he says that he used a different kind of donation of mitochondria to achieve five other health births for people with infertility. He says: “In total, 15 children were before me.”

But he adds that other clinics in Ukraine also use donuts, without sharing their results. “We do not know the actual number of these children in Ukraine,” Mazur says. “But there are dozens of them.”

In 2020, Nuno Costa described the embryos in Barcelona, Spain, and his colleagues, another experience of donating mitochondria. This experiment, conducted in Greece, is also designed to test the procedure for people with infertility. It included 25 patients. So far, seven children were born. “I think it is a bit strange that they are not getting more credit,” says Heidi Mertz, a medical ethics expert at Gang University in Belgium.

The newly announced UK birth is only the latest “three of the three people.” Although their birth is announced as a success story to donate mitochondria, the story is not very simple. Three of the eight children were born with an unimportant percentage of transformed mitochondria, ranging from 5 % and 20 %, depending on the child and the sample.

Dagan Wales of Oxford University, who is involved in the trial of Greece, says two of the seven children in their studies seem to have inherited Mtdna from their intended mothers. Mazur says he has seen several cases of “reflection” as well.

This is not a problem for children whose mothers do not carry genes for mitochondria. But it may be for those whose mothers do.

I don’t want to put cold water on the results of the new UK. It was finally wonderful to see the results of an eight -year -old experience. The births of healthy children are something to celebrate. But it is not a simple success story. Donorly donate does not guarantee a healthy child. We still have more to learn, not only from these children, but from others who were already born.

This article appeared for the first time in the examination, Massachusetts Institute of Technology Review Weekly newsletter of biotechnology. To receive it in your inbox every Thursday, read articles like this first, Subscribe here.

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2025-07-18 09:00:00