Birth of a baby to "three parents", forgetting the future

A Jordanian couple living in New York have just had a child by using part of a third person's egg. This is the first baby born to "three parents" according to the media, a genetically abusive name. Both fertilization and birth took place in Mexico due to the ban on the practice in the United States.

Lhe announcement of this birth dated April 6 was made on September 27. It is not actually the first child born thanks to three different materials, but he is the first born in good health, say the doctors, and following this method of cytoplasmic transfer. This is why his birth is treated as unheard of.

Abrahim Hassan was born through a technique that is currently only officially authorized in the UK, but the legislative vacuum over this practice in Mexico has prompted theAmerican Society for Reproductive Medicine to carry out its work there, this procreation technique having been banned for several years in the United States because of the risks as to the fate of the child.

The beneficiary couple had already lost two children, died of a necrotizing encephalomyopathy, Leigh syndrome, transmitted by the mitochondria of the mother who, moreover, had already had two miscarriages. It is in order to avoid this transmission of mitochondrial DNA by the mother, a healthy carrier of this syndrome which attacks the muscles and the brain especially in newborns, that Dr. Zhang's team proceeded to the substitution of mitochondria whose mutations could have caused this genetic disease.

The disease is transmitted only from mother to child via the mitochondrial genome (MtDNA) contained in the envelope of his oocyte. To get around this fact, Dr. Zhang, assisted by his team from New Hope Fertility Center of New York, provided a new envelope for the mother's chromosomes by extracting the nucleus of the oocyte which it integrated into the healthy and enucleated oocyte of a donor before proceeding to fertilization.

The child thus conceived thus has three DNAs, the healthy ones of his parents and the healthy mtDNA of a third person. The method differs somewhat from that followed in British laboratories where an oocyte is fertilized before being stripped of its nucleus and receiving another from an egg also fertilized by the same donor. The Jordanian couple refused this possibility in the name of their Muslim beliefs so as not to remove an already fertilized egg.

Five eggs had been fertilized, and the only healthy one of the four viable ones had been implanted. It is not therefore, contrary to what is said by oversimplification, of a child with three parents in the strictly genetic sense of the term, the support of heredity being in the nucleus, even if a small part of the DNA is located in the mitochondria. But the child receives a share from a third party as if he had received it from his mother. However, the third party's DNA would not be found in some children already designed using this method.

The interest for the couple was to preserve the genetic heritage of the chromosomes located in the cell nucleus of the mother. Zhang's team believes they made the right decision, claiming that “Saving lives is the ethical thing to do”, reports New Scientist. A moral justification that reverses the facts.

Positivist rationale for relativism in parenthood

A person who does not exist does not need to be saved. The life saved argument can only surprise here when it comes to creating a child, admittedly free from an orphan disease but non-existent when the decision was made. This justification is always, in one form or another, that of a scientist vision of the world, which poses science as a source of values, and which Henri Poincaré denounced, who challenged science to express itself to the imperative instead of speaking and analyzing in a neutral or descriptive manner in the indicative. The argument of success also makes say to New Scientist his hope to see the technique develop rapidly and all over the world.

Another ethical argument advanced in the prestigious British scientific journal is that of the moral superiority of the method followed by Dr. Zhang's team. Sian Harding, Professor of Cardiac Pharmacology at theImperial College London, who says: “The team avoided destroying any embryos, and they used a male one so that the unborn child would not die from transmitted mtDNA. It's as good if not better than what we would do in the UK. ”

As the Jordanian couple refused the British method because of their religious beliefs, it can be assumed that they refused to resort to full adoption, prohibited in Islam. Either way, he chose to have a child close to his phenotype, just like him. This decision, which involves a third-party donor in the conception of the child, risks triggering a quest for origins in the latter. It would be possible to attempt the comparison with organ donation to speak of a saved child, of the latter's satisfaction with existing thanks to a donation, but the situation is radically - and this in the etymological sense - different: it does not it was not a question of healing, of curing; it was a question of conceiving. The child does not yet live thanks to an organ from a donor, it exists because a third party has donated his mitochondrial DNA, and he is very likely to ask himself the question of his own identity, as children born. of gamete donations with heterologous donors.

Attempting to answer this hypothesis of this risk, Dr John Appelby, of the Center for Ethics and Medical Legislation of the King’s College, in London, dares a comparison between children born from a sperm or oocyte donation and those born following a cytoplasmic transfer. He believes that children born from donated gametes do not understand their identity in a genetic sense and therefore proximity to heterologous donors but seek to know them for other reasons, and that it must be assumed that the same is true for children born with mitochondrial replacement, especially since mtDNA represents much less than the nuclear genome and is therefore not supposed to have the same consequences on the phenotype of the child born from “three DNAs” as does the nuclear genome. A hypothesis to justify a risk posed to the unborn child whose existence is by definition not known and deserves to be treated on the basis of the precautionary principle, especially since the risk will not be limited to biological fact but will be likely to affect the psyche.

Irresponsibility of the medical risk posed to the child

Ethical questions with regard to psychological risk also find a counterpart in relation to medical risk. If the Food and Drugs Agency (FDA) has banned this practice in the United States, because its consequences are not under control. In the early 2000s, around XNUMX children had been conceived in the country using a different method, the injection of mitochondria into the egg in order to revitalize the mitochondrial part of the oocyte in women who experienced a decline in fertility due to their age; in a sample of 12 pregnancies, a two-embryo X chromosome was missing, and among the other children who developed normally, one eventually developed autism-like disorders. Cause or correlation, the federal agency did not wait to be able to decide and applied the precautionary principle. Julie Steffan, professor of genetics at Necker Hospital in Paris, notes the medical risk for the child thus conceived:

"There was indeed research that was done with an animal model, in this case the mouse, and in the end the results showed that this transfer technique was not harmless, the mice born having neurological disorders . " 

The FDA, which says it is encouraged by the progress seen through the trials, expressed its reservations about the risks in a document from February 2014:“The consequences of incompatibility between nucleus and mitochondria, or nucleo-cytoplasmic epigenetic effects, as a consequence of these mitochondrial manipulation technologies are not fully understood. " La National Academy of Medicine believes these "babies with three parents" could be the solution for carriers at high risk of rare and deeply destructive genetic diseases to have healthy children who are genetically theirs, but that the FDA should be cautious about such experiments. It asks, on the medical level, to retain only the male embryos in order to further reduce the risk of transmission of mitochondrial diseases, and, on the psychological level, to follow the course of these children to assess the social and psychological impact of this technique.

For now, Marcy Darnovsky, director of Center for Genetics and Society blames Dr. Zhang's team for deliberately choosing Mexico "in order to circumvent the protocols and standards in force in the United States." She recalls that “the doctor is not justified in ignoring the accepted rules and applying his own, at the risk of setting a dangerous precedent. Indeed, the technique is not mastered and the children thus conceived almost come under the guinea pig.

In the United Kingdom, where research on this technique is very advanced, the risk of transmission of a mitochondrial disease was reduced, but in 2015, after testing their technique on human embryos, British scientists found that 4% of the DNA that had mutated had passed to the embryos and that, even after the embryos were destroyed after six days, mutated DNA transmitted by mitochondria increased in preserved and cultured cells to the point of disease. Dr. Zhang thus took the risk of conceiving in vivo a child below US legal protection.

The decision to place these risks on the unborn child evokes the words of the philosopher Hans Jonas, in For an ethics of the future, concerning this prospective morality which could also be applied here:

"The need has become obvious because our action today, under the sign of a globalization of technology, has become big for the future, in the threatening sense of the term, which moral responsibility imposes to take into account. consideration, in the course of our daily decisions, the good of those who will be subsequently affected by it without having been consulted. ".

Hans-Søren Dag

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