Hedi L. Claahsen – van der Grinten is paediatric endocrinologist and head of the department of pediatric endocrinology at the Radboud University Nijmegen Medical Centre, the Netherlands. She graduated as MD in1995 and followed her paediatric training at the Radboud University Nijmegen Medical Centre. In 2002 she started her training in Paediatric Endocrinology at the Department of Paediatric Endocrinology of the Radboud University Nijmegen Medical Centre, The Netherlands. She was registered as paediatric endocrinologist in January 2007 and graduated as PhD in 2007 with the thesis entitled “Adrenal rest tumours in congenital adrenal hyperplasia”. Her research line focuses on different aspects of congenital adrenal hyperplasia (CAH) and other forms of disorders/differences of sex development (DSD), with emphasis on the etiology of testicular adrenal rest tumours (TART) and the role of steroid precursors in CAH. She is chair of the national congenital adrenal hyperplasia working group and founding member and member of the steering committee of the Radboud Adrenal Centre, Nijmegen that serves as an expertise centre for the diagnosis and treatment of adrenal diseases, both in children and adults. Furthermore, she is founding member and leading coordinator of the Radboud DSD expert centre, Nijmegen. Since 2015 she is member of the medical ethical comite of the Radboudumc.