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A Chinese researcher from the University of Shenzhen claims to have helped create the world's first genetically modified children. Dr. He Jiankui reported genetically modifying – with the CRISPR / CAS9 technique – embryos that were made during development, creating "literally" two "twins" resistant to the AIDS virus ".
It is important to note that – while we are writing this article – there is still no independent confirmation of this discovery and there does not appear to be a scientific article to support the experiment: a fact that is certainly not unimportant, given the magnitude of the hypothetical "conquest". scientific knowledge of which one could hope for a claim of authenticity and paternity beyond all illusion.
But how did he intervene on the embryos of HIV-positive couples involved in the Chinese experience? It is obvious that the use of gene editing, gene therapy technique, in which a specific cellular DNA sequence, called "target", is directly modified. The modification event is achieved essentially by introducing an external DNA sequence inside the cells, able to specifically recognize the target sequence and perform a specific conversion.
This technique, initially applied to the construction of transgenic mice, was then adapted to the gene therapy protocols of hereditary diseases, then to the restoration of a "normal phenotype", modified as a result of the presence of transgenic mice. a defective gene. In this way, the exact gene information is provided to the cells, which restores the normal structure and correct functioning of the protein in the mutated cells. The benefits of gene editing in gene therapy protocols are different. The correction of the gene abnormality occurs in a specific way. It can therefore be applied to the treatment of genetic diseases, regardless of the size of the gene. The correction is permanent and preserves the integrity of the gene, that is to say, to keep the "switches" of the gene unchanged, leaving unchanged the mechanisms of operation.
The concern lies in the fact that these techniques, certainly simpler than those used up to now, would correct DNA even in embryonic cells or gametes (oocytes or spermatozoa), thus allowing the birth of genetically modified babies, especially in countries where controls and authorizations for genetic engineering experiments are easy to master.
This seems to have happened in China, where there is no specific legislation on this subject: in America, the technique of gene modification is prohibited on embryos, in Italy law 40 imposes many restrictions, but paragraph 3 of Article 13 leaves an opening, even an obligation to intervene – in case of diseases of embryos, in order to be able to treat them ("any form of selection for eugenics is forbidden, with the exception of diagnostic and therapeutic").
Gene editing technology has been used successfully on many animal models and experimental models of monkeys and more recently on embryonic stem cells and gametes such as spermatozoa and oocytes.
The "Nuffield Council on Bioethics" recently concluded that the use of genetic editing on embryos, sperm or human ova could only be considered "morally acceptable" in some cases. Consider, for example, the possibility of correcting the defective gene that causes "sudden death" in families where this gene has been transmitted for generations and where each newborn is at 50% risk of inheriting this gene and therefore have caused the disease for example during a football match or in the case of well identified hereditary tumors. Genetic editing could permanently eliminate these defective genes in these families.
The "improvement" genetic, as in the case of Chinese experience, always confirmed, represents an absolute novelty, not without questions. It is technically possible to insert genetic verification interventions into badisted procreation, to ensure certain somatic characteristics in unborn children or resistance to certain diseases, but what is its usefulness or relevance? It depends on us, the seriousness of scientists and society: there are precise protocols and guidelines developed by the major international scientific societies, so that any genetic modification can be considered morally and ethically acceptable. In this case, Chinese researchers have crossed these boundaries, inactivating the CCR5 gene that allows born twins to resist HIV infection.
It's like blocking one of the main gateways of the HIV virus into our cells: a condition already existing in nature, with about 2% of the European population born with this "door" blocked , on which many studies have been based the identification of drugs capable of modifying the receptors involved. This condition however does not guarantee a 100% prevention of the infection because the virus could use other access even with difficulties. In addition, it is known that blocking this port increases the risk of being infected with other viruses, such as West Nile virus.
And therefore: it would not be better to spend money, skills and research efforts to work on improving existing and effective drugs to combat HIV transmission by the mother and the fetus. push to contain epidemics with correct prevention protocols, and use new genetic engineering techniques to treat diseases rather than creating super-individuals?
In my opinion, genetic modification of embryos, to be ethically and morally acceptable, must be oriented towards two fundamental principles: (a) each intervention must aim to ensure the well-being of the future person and / or his descendants; b) no intervention should benefit, disadvantage, discriminate or create divisions in our society.
Added to this are doubts about technology (these problems are certainly solved). Some British researchers have discovered that Crispr / Cas9 can cause genetic damage (rearrangements, deletions, insertions) at other than correct points, it is as if one corrects, leaves traces or deletes upstream or downstream of the sentence correct. This could lead to the activation or deactivation of important genes, with very serious consequences. It is possible that the technique will be refined over the next few months. In fact, other forms of Crispr / Cas9 using other proteins have been discovered and will certainly make correction more accurate and risk free.
The only way to eliminate these fears is to launch open discussions on the subject within the scientific community through conferences and specialist forums and especially by supporting research, the only antidote to fear and ignorance .
If you have corrections, suggestions or comments, write to [email protected]
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