We are on the verge of a revolution whose consequences last we can't even imagine. The accumulated knowledge in biology and genetics will allow, as explained by the historian Yuval Noah Harari, Homo Sapiens becoming a species of Homo Deus, able to determine their own biological destiny. You will be able to alter the genetic heritage of any species, including humans, and on the horizon is the possibility of creating human genetically enhanced. But to open those doors must be very sure that you comply with two important requirements: that there is a clear consensus on the desirability of doing so because it provides benefits indisputable, and that can be done with security assurances. In science, not everything that is possible is desirable, but if we come to the conclusion that what is must be possible to do so in conditions which respect the principle of non-maleficence.

I have Jianchui has shown that it is possible to intervene at the embryonic level to turn off the gene that allows the aids virus to colonize and neutralize the immune system of the infected person and to make that protection is passed on to the offspring. But it has been released to the experiment without taking into account the limitations that still has the technique and without being able to ensure that will not have adverse effects.

When in 2012 it was discovered the technique of edition genetics, CRISPR/Cas9, which allows you to cut and paste pieces of DNA accurately, many thought that the promises of gene therapy would last. The death of Jessie Gelsinger, one of the first patients who were tested, showed that the scientists had been precipitated. Missing knowledge on the side effects and the fiasco of the first tests froze its development for decades. Science advances sometimes blow of discoveries disruptive, and the technique of CRISPR/cas9 definitely is. In just six years their use has become widespread. But as they warn their descubridoras, Emmanuel Charpentier and Jernnifer Douda, you have to be cautious of applying it in humans. Of time has been allowed to cure deafness in mice, creating animals that are genetically modified to express human disease and can test drugs on them; it has allowed to modify a strain of mosquitoes, to avoid transmitting malaria; the own Carpenter uses to find a way to neutralize bacteria resistant to antibiotics... and a long list of promising developments. But it is still not safe enough and that's why the human experiments are adopted in a piecemeal way. The first applications, however, are already coming to the clinic to treat with immunotherapy in some types of cancer. In this case, are extracted from the T lymphocytes of the immune system of the patient and are modified by CRISPR several of the genes, so that when you reintroduce them in the body, can identify and attack selectively to cancer cells.

Go beyond that in order to play god involves many risks, as do the scientists know better than anyone else. It is not by chance that exists in the scientific community a general consensus that prohibits applying genetic modifications to the germ cells. It is one thing to cause a genetic alteration that only have consequences on the individual on which it is applied, and quite another to do it so that their effects can be transmitted to the offspring, which is what he has done for the first time that we know and absolutely irresponsible geneticist I have Jianchui.

William Betenson, the scientist who coined the term genetics, already predicted at the beginning of the TWENTIETH century that “the exact determination of the laws of inheritance will lead to more changes in the attitude of man toward the world and his mastery of nature that no other progress that can be achieved”. We are on the verge of a great revolution. The temptation to seek shortcuts to achieve glory and wealth will be increasingly strong. That is why it is important that the consensus of prudence that there is now to be translated into applicable legislation throughout the world.