Born in Strasbourg in 1946.
Doctor of Medicine and Doctor of Science. He was Professor of Genetics at the Strasbourg Faculty of Medicine until his appointment to the Collège de France on November1, 2003. From September 2002 to September 2009, he was Director, then Deputy Director of the IGBMC (Institute of Genetics and Molecular and Cellular Biology of the CNRS, INSERM and University of Strasbourg).
Since 1982, he has led a research team dedicated to the analysis of genetic diseases. His laboratory has identified a dozen genes responsible, when mutated, for hereditary diseases affecting the nervous system or muscle.
In 1991, Jean-Louis Mandel and his colleagues discovered a new type of mutation, an unstable expansion of trinucleotide repeats, responsible for fragile X mental retardation syndrome, the most common cause of familial mental retardation. Unstable mutations have subsequently been shown to be responsible for more than 15 neurological diseases, for which they explain the anomalies in familial transmission.
Jean-Louis Mandel's laboratory has made a major contribution to demonstrating the mechanism of trinucleotide expansion in other pathologies (spino-cerebellar ataxias type 2 and 7, Friedreich's ataxia), to understanding the stepwise evolution of these mutations in human populations, and to understanding the pathological mechanisms induced by these mutations (for fragile X, Huntington's disease, and Friedreich's ataxia).
His laboratory has also identified genes with unexpected functions in other neurological and muscular diseases: adrenoleukodystrophy (a very severe demyelinating disease), ataxia with vitamin E deficiency (and discovery of a high frequency of this disease in North African populations), myotubular myopathy (discovery of a new family of phosphatases, conserved in all eukaryotic organisms, and demonstration of its involvement in phosphoinositide metabolism), Coffin-Lowry syndrome. He is now focusing on the pathophysiological mechanisms of several of these diseases, using animal and cell models.
Jean-Louis Mandel has also developed diagnostic and genetic counseling tests for Fragile X syndrome and several other diseases. He heads a major laboratory for the molecular diagnosis of genetic diseases at Strasbourg University Hospital. He is a member of the scientific advisory boards of several associations for patients and families affected by various genetic diseases.