“Three
DNA” babies
Mitochondria are the "power plants" of
cells; they have their own DNA, which is passed through the mother. The most
common signs of a mitochondrial disease are a myopathy or excessive muscular
fatigue, cardiomyopathy, a decrease in vision and hearing, and often also
severe neurological signs: encephalopathy, epilepsy, dementia, ataxia... They
hit about a newborn on 6500.In February 2015, the British Parliament approved in vitro fertilization with mitochondrial replacement. When a woman is at risk of transmitting a mitochondrial disease, she can be proposed a fertilization in vitro, with maternal oocytes from only the core has been kept, the oocyte donor, separated from its kernel and containing healthy mitochondria, and sperm from her husband or partner. The child to be born was born will have three biological parents, three different DNAs. David Cameron, (one of his children died at 6 years old) commented the vote: "If science can help (...), we must ensure that these treatments are available"; and, for the Minister of health, it is "the light at the end of a dark tunnel". This treatment is not allowed in France. Ethics beyond the Channel, morally prohibited on the other side ; light beyond, darkness on the other side!
Genetic
manipulation on the human embryo
In April 2015, a Chinese team has published the
first attempt of gene therapy on a human embryo. It was embryos with a genetic mutation causing beta Thalassemia (a deficient
haemoglobin that can result in severe anaemia). Using the new opportunities of
'genetic edition' , the crispR/case9 techniques (possibility to insert much
more specifically a gene at a particular location), Chinese researchers have
attempted to replace the mutant by a functional hemoglobin gene. Let say first that the result was quite disappointing:
genetic modification expected occurred in 4 embryos on 54, and insertions have
occurred in significant numbers in other parts of the genome. The Chinese team
recognize: the technique is far from being mature enough to consider
therapeutic human cloning. In this case, it was only an experiment on unviable human embryos, from an IVF attempt, intended
for research, with consent of the donors, and without intent of go to birth. However, these manipulations on the human embryo are prohibited in almost all Western countries, and a number of researchers have called for a moratorium on this type of research in Nature... not even a month before the publication of the Chinese study (refused by some major scientific journals). Clearly, this moratorium cannot stand - apart from being inefficient, it is even ethical ? Research will continue in the West or elsewhere and, probably one day, the technique will correct very reliably a mutation in a human embryo. Will we consider the baby that is born to be a clone (horror?), or simply a cured baby (great!)?
There again, the scientific community is shared. Nicole Le Douarin, Pr at the College de Franceis rather supportive : "I'm for progress, not to fear. Do not dismiss this technique, because it can have very interesting applications, provided that they are strictly supervised. Imagine that this could allow in the future to eradicate a monogenic disease like cystic fibrosis... "(Science et avenir, June 2015). Axel Kahn spoked of " fame for media” and “symbolic of the forbidden and the scandalous" and precised "there is a much easier and safe way to allow the birth of a healthy child: prenatal diagnosis or preimplantation, with elimination of embryos carrying a genetic defect”. Declarations of past or present members of the National Consultative Ethics Committee startling me more and more. On behalf of what, instead of who dopes he have the right to decide that the elimination of defective embryos is more ethical than looking for techniques to treat them?
Preimplantation genetic diagnosis (selection of
embryos) for breast cancer
For the first time in France, a couple whose
wife carries the BRCA1 mutation, predisposing them to breast (risk multiplied
by 4-6) and ovarian (risk multiplied by 10 to 50) was authorized to take a
preimplantation genetic diagnosis, so as to ensure that the child born by IVF will
not be affected. This had already been accepted for other cancers where genetic
determinism is even more important (retinoblastoma, Li Fraumeni) . This process
is authorized since 2009 in England (gain, the Channel as ethical barrier!); In
France, so far, all applications had been denied (by whom, in what name?). A
2008 report recommended for BRCA1 and A2 genes not to propose a pre
implantation diagnosis, except in some cases "where demand would similarly
admissible» (by whom, in what name?)." Onco geneticist Pascal Pujol speaks
"of an incredible subjectivity" (Le
Monde, mercredi17 June 2015). And if one accepts the possible use of
preimplantation diagnosis, I see no reason to deny freedom of BRCA1 testing, as
proposed, for example,by 23andme. In short, when France moves in
this area, it is in arbitrariness and injustice.
Yes, it really is time that the National
Consultative Ethics Committee starts to work - the arbitrary and unjust are
accumulating. It is time also to put in the foreground the will of patients and
society in general; to listen a little less those who, for religious reasons or
by medical routine, thrive well of a humanity which should for ever a suffering
humanity. The positivist I am would consider ethics, very simply, as any
sufficiently safe technique which can alleviate people’s woe…
Aucun commentaire:
Enregistrer un commentaire
Commentaires
Remarque : Seul un membre de ce blog est autorisé à enregistrer un commentaire.