How different we are from each other! Everyone sees and does things in their own way. None of us are free of prejudice. We need to recognize this. This is not a confession of moral relativism, but the simple observation of the resounding fact that each one of us shapes, day by day and in our own way, our lives, what we do, what we think. We live being different.

Diversity - diversity Genetics included - is a priceless asset that gives each and every one of us the privilege of being unique, unrepeatable. That is source of countless blessings. It allows us to adapt, as individuals and as a community, to the myriad circumstances in which we find ourselves.

A decisive part of this diversity is inscribed in our very origin. It emerges from the fact that meiosis assigns to each gamete and, consequently, to each one of us at the moment we are begotten a unique genome of our own. This not only influences the structure and function of our body. It plays a relevant role in the way in which each one of us interprets the world; in the staff and non-transferable way of seeing, hearing, thinking, enjoying or praying; in the lifestyle that we freely and responsibly choose. Diversity is the salt and pepper of life.

But diversity also has its counterpart. Like everything else in life, the complex molecular and cellular mechanisms that create diversity sometimes fail, and then manifest themselves in a variegated variety of anomalies, predispositions and diseases: some, happily, minimal; others, serious.

There is nothing strange about that. I was a pathologist years ago and I have seen the many ravages that disease wreaks on bodies. As a consequence, one idea has stuck with me: in life, biological failures provoke successes. They awaken, in a kind of permanent miracle, a vast variety of adjustments, balances and compensations. Mistakes are source endless surprises. Lewis Thomas expressed it in a masterly way when he referred to the capacity of that marvelous molecule DNA to make mistakes, as if it had been designed to make mistakes and then somehow mend them.

Thomas said: "And so, at some point in our past, a pair of nucleotides broke apart to let in a new one, or allowed a virus to sneak in a fragment of a foreign genome, or cosmic radiation to cause some damage. And, thanks to that, man appeared in the world".

We would not have become what we are biologically, nor be so different from each other, without the accommodating capacity of that molecule, at once so fragile and so tenacious. And that has its price. Chromosomal diseases and genetic alterations are the necessary accompaniment to the immense advantages that DNA has brought us. We must accept that its mistakes are as much ours as its successes.

We all carry in our genome some mistakes. Some go unnoticed, others manifest themselves late in life. Others even before we are born. Many societies have adopted the violent tactic of "point and shoot" in the face of genetic damage, in order to get rid of all "junk Genetics".

The eugenic mentality, the demand for the perfect child, seems to me to be dehumanizing, intolerant, because in its purifying zeal it carries away not only children with defects from development, but many normal children, victims of false positives and of the collateral damage of invasive prenatal diagnosis.

It is a brutal zeal that, in order to avoid the risk of being taken to court for having allowed the entrance in the world of a child with development defects, does not hesitate to sacrifice normal children, for whom no one will demand responsibility.

I firmly believe that there is a right - more than human, very human - to suffer from genetic errors and, despite this, to be accepted by all, not to be discriminated against. It is, it seems to me, a primary right that emerges from the most essential part of our biology, which we all enjoy without exception.

Many years ago I launched a challenge to the promoters of the idea of the perfect baby: "Let him who is clean of genetic mistakes cast the first stone". I said it one day, years ago, in Strasbourg, in a joint meeting of the Legal Commission of the committee of Europe and the association World Association of Children's Friends. And I added: "Fortunately I was born before sophisticated prenatal diagnosis existed. Today I could have been eliminated because of my little handicaps: my predisposition to deafness, my hiatus hernia, my short little fingers! According to the Fanconi, the Pediatrics book I studied, my short pinkies marked me as a carrier of degenerative stigmata".

I showed my hands and, to general astonishment, two members of the presidential table (the Princess of Bourbon-Lobkowicz and the University Secretary of committee) shared my short pinkies.

May God save us and future generations from the fanatics of perfection Genetics. May they please let us live with our mistakes.