Nathalie Josso

Nathalie Mühlstein Josso (1934-2022) was a pediatric endocrinologist who studied variations in genital development before birth, including intersex.

[8][6] Soon after finishing her residency in paediatrics, Josso decided to pursue a scientific career at INSERM, the French national institute for health and medical research.

[6][9] In addition, when she studied endocrinology her professor was Alfred Jost, who had postulated the existence of a hormone other than testosterone that helped determine male sex after a series of experiments in the 1940s.

[6][10][11] Josso gained her PhD in 1971 from the Pierre and Marie Curie University, with a dissertation on Wolffian ducts in fetal rats, under Jost's supervision.

She wanted to work on discovering Jost's unidentified substance, and moved to do so at a new INSERM laboratory at the Necker-Enfants Malades Hospital, where she had done her paediatric training.

[13] From 1986 to 1998, Josso was the founding research director for the INSERM developmental endocrinology unit at the Ecole Normale Supérieure.

[18] The group's results included the development of a blood test for AMH, and identifying the genetic origin of Persistent Müllerian duct syndrome.