Pope Leo pays tribute to Jérôme Lejeune, defender of human dignity
Pope Leo XIV honored Venerable Professor Jérôme Lejeune on the centenary of his birth, praising his work in genetics and defense of human dignity. He highlighted Lejeune's discovery of the chromosomal abnormality causing trisomy 21 and his advocacy against eugenics and chromosomal racism. The Pope urged foundation members to emulate Lejeune's commitment to the common good and to serve those most vulnerable. He warned that technology should not replace ethics in medicine, stressing that life decisions must not be based solely on algorithms. The meeting included participants from several countries, underscoring the international nature of the foundation's mission.
3 months ago
Pope Leo XIV used the centenary of Jérôme Lejeune’s birth to reaffirm the Church’s defense of human life, highlighting the French geneticist’s scientific contributions, his advocacy for people with Down syndrome, and his opposition to any form of “chromosomal racism.” He called on doctors, researchers, and the wider society to follow Lejeune’s example and ensure that medicine never becomes a tool for programmed death. 1 2
Pope Leo XIV received members of the Jérôme Lejeune Foundation and praised Lejeune as a “pioneer of modern genetics” who discovered the trisomy‑21 chromosome abnormality. 1
The pontiff recalled that Lejeune was appointed by Pope Paul VI to the Pontifical Academy of Sciences and that his friendship with Pope John Paul II helped shape the Pontifical Academy for Life. 1
Lejeune’s work, the Pope emphasized, led him to confront the prospect of prenatal elimination of embryos with Down syndrome, which he denounced as “chromosomal racism” and a violation of the Hippocratic oath. 1 2
He is described as having “defended the life and dignity of the most vulnerable, even at the cost of his career,” and his cause for beatification is underway, with the title of Venerable granted in 2021. 2
Leo XIV warned that doctors must never decide the fate of an embryo or an elderly person based on algorithms or efficiency considerations. “Medicine can never become the servant of programmed death,” he declared. 1 2
He stressed that technology, while helpful, cannot replace ethical judgment and should never be used to justify “planned death” or eugenic practices. 2
The Pope urged the foundation’s members, families, and healthcare professionals from many countries to continue Lejeune’s mission of serving the common good, especially for those “living with frailty or disability.” 1
He expressed hope that Lejeune’s example would inspire “the courage of truth” in young people and professionals, uniting reason, faith, and compassion without judgment. 2
The address came as France’s National Assembly debates a “right‑to‑die” law, and the Pope’s remarks were seen as a moral counter‑point to proposals that could legalize euthanasia. 2*
Does the Church’s teaching on human dignity oppose eugenics and chromosomal discrimination?
Yes. Catholic teaching on human dignity opposes eugenics and “chromosomal discrimination”—especially where genetic/physical conditions are used as criteria to deny persons’ rights, suppress embryos or fetuses, or treat some lives as less worthy of protection.
The Church teaches that human life is sacred from its beginning because it involves God’s creative action and remains in a special relationship with its Creator; therefore, it is not lawful to directly destroy an innocent human being.
Building on that, the Congregation for the Doctrine of the Faith explains that the Magisterium’s “no” to certain practices (including those affecting very early life) is not rejection of science, but a positive “yes” to the dignity of every single human being—especially the vulnerable who have “no voice.”
St. John Paul II explicitly denounces “a new selective eugenics” that leads to the suppression of embryos and foetuses suffering from disease, and he rejects the use of selective stages of prenatal development to justify discrimination.
He further states that the rights protecting the human genome and the right to life must be enjoyed by every human being from fertilization “without any form of discrimination,” including discrimination related to genetic imperfections or physical defects and different developmental stages.
The Pontifical Academy for Life echoes this concern, describing how a cultural climate has fostered prenatal diagnosis and pre-implantations that are not therapeutic but discriminatory, resulting in attempts on the very lives of those who are “not healthy or perfect” from the earliest stages.
“Chromosomal discrimination” is often practical/ethical shorthand for treating people (or unborn persons) as less deserving because of a chromosomal condition (such as Down syndrome—trisomy 21).
Catholic teaching directly addresses this attitude. In a message to a symposium on trisomy conditions, St. John Paul II stresses that the term “special” used for people whose makeup or behavior differs from what is considered “normal” must not erase their personhood: the person “is still a human person, possessing the same inalienable dignity and deserving exactly the same respect as any other person.”
He also notes that selective abortion as a means of preventing the birth of handicapped children requires a “firm response from Christians,” grounding that response in the law of God and the defense of vulnerable, unborn life.
The Church is not teaching that all genetic knowledge or medical care is wrong. Rather, it draws a moral line at whether the use of such knowledge is therapeutic and protective of life, or discriminatory—leading to suppression or denial of rights.
That is why the Pontifical Academy for Life specifically criticizes prenatal diagnosis and pre-implantation practices “no longer therapeutic, but rather discriminatory.”
Because every human person has inviolable dignity from conception, the Church teaches that practices amounting to eugenics—including “selective eugenics” that suppresses embryos/fetuses based on genetic or physical traits—are gravely opposed.
Likewise, attitudes and policies that treat people with chromosomal conditions as less worthy or justify ending their lives are contrary to the Church’s insistence on equal respect for all persons with inherited or developmental differences.