The vision of the guardian on the mitochondrial donation: IVF innovation leads to a cautious genetic triumph | Editorial

Eight babies were born without a disease that can lead to terrible suffering and early deaths, thanks to pioneering scientists in the United Kingdom using a form of genetic engineering which is prohibited in certain countries, including the United States and France. Ten years ago, when the government and the regulators planned to allow the authorization of mitochondrial transfer technology, criticisms warned of “Frankenstein Meddling” which would lead to children to three parents. It is now difficult to justify such hostility in the face of meticulous work carried out by the scientific and medical teams of Newcastle, which led to these healthy babies and these ecstatic families.

Mitochondria, like tiny batteries, provide energy with each cell of the body. Their DNA is transmitted in the mother’s egg to the child. In rare cases, there are genetic mutations, which means that the baby can develop a mitochondrial disease. About one in 5,000 people are affected, making it one of the most common hereditary disorders. As cellular batteries fail in various organs, the child can feel a range of symptoms, from muscle weakness to epilepsy, encephalopathy, blindness, hearing loss and diabetes. In serious cases, they die young.

There is not yet a remedy, so the objective is prevention. Women who have damaged mitochondria and mitochondria can have genetic IVF and pre-implantation (PGT) tests to select embryos that are obvious to mutations or only slightly affected. The options for women with 100% mutated mitochondria were limited to the eggs or the adoption given – until the Parliament changed the rules to allow technology in 2015 and the Newcastle Fertility Center obtained a license in the fertilization authorization and human embryology to use it in 2017.

The process involves three people. The egg of the potential mother and a donor egg are both fertilized by man’s sperm. The core of the given egg is removed and replaced by the nucleus of the woman’s egg, but its healthy mitochondria remain. This composite egg is inserted into the woman’s uterus. The resulting baby’s DNA will be 99.9% compared to parents and only 0.1% of the donor. Barely a child with three parents.

However, there are controversies. Some countries will not make it possible to use technology due to concerns about the genetic modification of the human germ line. DNA mixed in the laboratory will be transmitted to future generations, with whom knows what consequences. And a question drags on something called inversion or reversion. Newcastle research results published in the New England Journal of Medicine show that some of the embryos with healthy mitochondria have developed mutations somewhere along the line. Mutations have been formed in 12% of the mitochondria of a baby and 16% in others. This was not enough to affect babies, who was healthy, but previous work from other scientists suggested that changes can increase over time, and no one still understands why.

Newcastle scientists and doctors have been much appreciated for their slow and methodical work. They brought joy to certain families and hope to others. But it is always an experimental technology and prudence is absolutely valid. And inevitably, there are cost problems. People who can afford it will no doubt pay, but the NHS is unlikely to be able to help the rest. Nevertheless, this revolutionary research must surely be authorized to continue, although in the same way attentive.

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