Pope Leo XIV issued a forceful defense of human life and the ends of medicine in an address last week on a pioneer of modern genetics, Jérôme Lejeune.

Dr Lejeune was a French pediatrician who discovered the genetic cause of Down Syndrome – Trisomy 21 – in 1958.

The Pope said he soon realised that his scientific discovery would be used “to eliminate people with Down syndrome before they were born”.

“He did not hesitate to become their defender, denouncing the violation of the Hippocratic Oath and what he called the new eugenics, describing it as ‘chromosomal racism’.”

It was a struggle that brought him harsh criticism in certain scientific circles.

The Pope quoted Professor Lejeune that “Medicine is the hatred of disease and the love of the patient” and that technology should never be used against the ends of medicine.

“For this reason, a physician should never be allowed to decide of the life of a particular embryo or a particular elderly person, on the basis of laboratory algorithms! Medicine must never become the servant of programmed death!”.

In some countries over 90pc of babies with Down Syndrome are aborted if a prenatal test reveals their condition.