Jerome Lejeune

Jerome Lejeune( Montrouge , Paris , 1926 – 3 from April of 1994 ), medical geneticist French and father of modern genetics. He discovered, among other things, that Down’s syndrome is due to the presence of an extra chromosome and described the cat’s meow syndrome , autosomal terminal deletion of the short arm of chromosome 5.

Biography and scientific contributions

After completing his medical studies, in 1952 he began working as a researcher at the CNRS , becoming director ten years later. He becomes France’s international expert on atomic radiation.

In 1958 , at the age of 32, he discovered the first chromosomal abnormality in man: trisomy 21 or Down’s Syndrome. Later, along with his collaborators, he discovers the mechanism of other chromosomal pathologies, thus opening the way to cytogenetics and modern genetics . He is considered as the father of modern genetics.

In 1964 he was appointed first Professor of Fundamental Genetics at the Faculty of Medicine of the University of Paris . The following year he was appointed head of the same specialty service at the Necker-Enfants Malades hospital in the French capital. He worked there until his death, caring for and treating hundreds of children and young people with Down Syndrome and other genetic pathologies; At the same time, continued research to understand and alleviate the effects of Down Syndrome, a cause of intellectual disability based on genetics, and diseases of genetic origin in general.

In 1974 , he was appointed member of the Pontifical Academy of Sciences .

In 1981 , the Academy of Moral and Political Sciences was made a member .

In 1983 he was appointed a member of the National Academy of Medicine . 1

He was Doctor Honoris Causa , member or laureate of numerous academies, universities or communities of foreign intellectuals. He was also a member of foreign academies, such as the Swedish Sciences , the American Humanities and Sciences ( Boston ), or the Royal Medical Society of London. He received numerous scientific awards, both in France and in other countries, and was recognized as one of the first world experts in genetics.

In 1994 , he was appointed the first President of the Pontifical Academy for Life for life .

He was also scientific adviser and one of the promoters of the association “Laissez-les vivre”, one of the first organizations pro of France. He was also president of “Secours aux futures mères”, an organization dedicated to helping pregnant women who are in difficult situations.

He married Birthe Lejeune and had 5 children.

On 28 June 2007, the cause of beatification and canonization of Professor Lejeune began . The diocesan process was concluded on April 11, 2012 at Notre Dame Cathedral in Paris . 2


  1. Back to top↑ Académie Nationale de Médecine
  2. Back to top↑ Association Les Amis du Professeur Jérôme Lejeune


  • Lejeune, Clara. Dr. Lejeune: Love for Life (1999), Ediciones Palabra, ISBN 978-84-8239-378-0
  • Lejeune, Jérôme [et al.] Medical and psychopedagogical advances on Down Syndrome (1991) Catalan Foundation Down Syndrome, ISBN 978-84-404-9513-6
  • Lejeune, Jérôme. What is the human embrion? (1993) Ediciones Rialp, ISBN 978-84-321-2975-9
  • Le Mené, Jean Marie. Professor Lejeune, founder of modern genetics (2013) Ediciones Encuentro, ISBN 978-84-269-0469-0