Catholic Scientist of the Past

Jérôme Lejeune

June 13, 1926 to April 3, 1994

Jérôme Jean Louis Marie Lejeune (June 13, 1926 to April 3, 1994) Lejeune was a French geneticist and pediatrician most famous for discovering in 1958, in collaboration with Raymond Turpin and Marthe Gautier, that Down Syndrome is caused by an extra copy of chromosome 21 (an example of trisomy). This was the first time that an intellectual disability was shown to be the result of a chromosomal abnormality.   Lejeune went on to discover the connection between several other diseases and chromosomal abnormalities. For his discoveries Lejeune was the recipient of many honors including the William Allan Award, the highest award of the American Society of Human Genetics.  Lejeune was very outspoken in defense of the unborn and named the first President of the Pontifical Academy for Life, a position he held for only a few weeks before he succumbed to cancer in April of 1994.  He has been named a “Servant of God” by the Catholic Church, the first stage in the process of canonization.

Copyright Information on Picture of Jérôme Lejeune  Picture credit: Fondation Jérôme Lejeune 

Explore Other Scientists

It is our hope that this curated set of biographies will be useful to teachers, students, and the general public.

Connect With Catholic Scientists

The Society of Catholic Scientists is an international organization that fosters fellowship among Catholic scientists and witnesses to the harmony of faith and reason.

Support Our Mission

Join the hundreds of people whose financial contributions are allowing Catholic scientists to engage with each other and the world as never before.

Another Callout Item

Lorem ipsum dolor sit amet, consectetur adipiscing elit. Vestibulum ullamcorper sed ligula in sodales. Sed sollicitudin dignissim turpis quis semper. Phasellus non est et nisl sodales dapibus vel quis ante.