IVF to three parents saves children in hereditary diseases, according to scientists

Eight children in the United Kingdom were spared from devastating genetic diseases thanks to a new in vitro fertilization technique to three parents. Moreover, scientists at Newcastle University reported on Wednesday.

This technique. Similarly, prohibited in the United States, consists in transferring elements of the nucleus of the fertilized ovum of the mother-namely the nucleus of the ovum and that of the father’s sperm-in a healthy egg provided by an anonymous donor.

The procedure thus prevents the transmission of mutated genes present in the mitochondria of the mother – true energy power plants of the cell – which could cause incurable. Therefore, potentially fatal disorders.

Mitochondrial DNA mutations can affect several organs. For example, in particular those with great energy needs, such as brain, liver, heart, muscles and kidneys.

Among the eight children born thanks to this technique. For example, one ivf three parents saves children is now 2 years old, two are between 1 and 2 years old, and five are still infants. All were in good health at birth. blood tests revealing none or very low levels of mutations in the mitochondrial gene, researchers said in the New England Journal of Medicine. All have also presented normal development, they say.

The results “are the culmination of decades of work”. not only on scientific and technical challenges, but also in matters of ethical reflection, mobilization of the public and patients, the development of laws and regulations, as well as the implementation of a monitoring system for mothers and infants, said in a press release Dr Andy Greenfield, specialist in reproductive medicine at the University of Oxford to research.

The “data mine” of researchers is expected to pave the way for new investigative avenues, says Greenfield.

Often. during procedures for selecting IVF oocytes, doctors can identify ivf three parents saves children a few eggs at low risk, with very few mutations in the mitochondrial genes, which are then able to be implemented.

But sometimes all the mother’s eggs bear mutations in mitochondrial DNA. In these cases, thanks to the new technique, British doctors first fertilize the mother’s egg with the father’s sperm. Then. they remove the “pronounces” from the fertilized egg-that is to say the ovum and sperm nuclei, which contain the genetic instructions of the two parents necessary for the development, survival and reproduction of the baby.

They then transfer these nuclei to a given fertilized egg, from which the pronoyals were removed.

The ovum of the donor will then begin to divide. develop with her healthy mitochondria, and nuclear DNA from the mother and the father.

This process. detailed in a second article in the journal, “essentially replaces the defective mitochondrial DNA (DNA) with a healthy DNA from the ivf three parents saves children donor,” said professor Mary Herbert, a reproductive biology specialist in Newcastle, during a press point.

The blood rates of DNA mutations were 95 % to 100 % lower in six newborns. and from 77 % to 88 % lower in two others, compared to the rates of the same variants in their mothers, researchers report in this second article.

“These data indicate that pronuclear transfer has been effective in reducing the transmission of DNA-related diseases,” they conclude.

The procedure was tested in 22 women whose babies were likely to inherit these genes. In addition to the eight women who have given birth to the children mentioned in this report. another is currently pregnant.

Seven of the eight pregnancies took place without complications. In one case, a pregnant woman has presented high levels of blood lipids.

No miscarriage has been identified.

The authors of the current relationships have also tried to ivf three parents saves children transplant the nucleus of an unfertilized ovum of the mother in a ovum of donor. then to fertilize the latter, but they consider that their new approach could prevent the transmission of genetic disorders more effectively.

In 2015, the United Kingdom became the first country in the world to legalize research on mitochondrial donation in humans.

In the same year. in the United States, pronuclear transfer was effectively prohibited for human use by a Congress finance law, prohibiting Food and Drug Administration from using funds to examine the use of “hereditary genetic modification”.

(Report by Nancy Lapid; writing by Michele Gershberg and Lisa Shumaker)