Earlier this month, a scientific article was published, according to which American researchers have succeeded in curing mice suffering from a disease Genetics. The scientists injected the animals with molecules capable of correcting "mistakes" in the genome with great precision, thus changing the disease-causing mutation for the correct letter in the gene in question. This technology has been being perfected for some years and, in fact, in 2011 it was already named "technology of the year" by the prestigious journal Nature Methods. The special thing about this new research is that for the first time it is being used to cure a hereditary disease in an animal by modifying the genome of its cells with great efficacy.

When, thirteen years ago now, the project Human Genome published the "final" version of our guide instructions, the sequence of the three billion letters that make up our genome, few of us thought that in such a short period of time we would have the technology to modify it with such precision. Today we can glimpse that genomic correction applied to human beings is not so far away, so the celebration of "DNA Day" seems to me to be an ideal moment to stop and reflect on the medical, ethical and social implications that this could bring with it. The medical advantages are unquestionable: the cure of hereditary diseases. But our genome also contains "letters" that, without directly causing a pathology, significantly increase the risk of suffering very frequent diseases (cardiovascular, degenerative). Correcting these "typos" early in childhood, or even in the fetal stage, will help to drastically reduce the prevalence of these diseases, which together constitute one of the main causes of death in developed societies. All this, together with improvements in health care and control of environmental factors, will lead to a significant increase in longevity and a myriad of social changes whose impact is difficult to foresee.

Likewise, the discussion on "the limit" will be inevitable because when it is possible to correct a disease-causing mutation, it will also be possible to change letters to improve other traits that have no particular medical implications, such as eye color or height. This entails the obvious risk of favoring a certain eugenic mentality, the consequences of which are also difficult to anticipate, especially in the field of disability.

And, finally, there remains the no less important question of universal access to these new technologies within the coverage of health systems that are probably overburdened, trying to avoid inequalities for geographic, economic or cultural reasons.

I am convinced that all these issues and others that probably escape me will be in full discussion by the year 2036 when we celebrate the twenty-fifth anniversary of the publication of our genome sequence. In my opinion, it is important that we begin to discuss all the ethical, legal and social ramifications that they will bring because they are certainly going to change the way we organize ourselves as a society. And we must make sure that the change is for the better.