1. Paediatrics and Adolescent Medicine, Faculty of Medicine, University of Augsburg , Augsburg 86156 , Germany
2. Department of Paediatrics, Paediatric Haematology/Oncology, Otto-von-Guericke-University , Magdeburg 39120 , Germany
3. Department of Paediatrics, Division of Paediatric Endocrinology and Diabetes, Christian-Albrechts-University Kiel & University Hospital Schleswig-Holstein , Kiel 24105 , Germany
4. Paediatric Endocrinology & Diabetology, Steroid Research & Mass Spectrometry Unit, Centre of Child and Adolescent Medicine, Justus Liebig University , Giessen 35392 , Germany
5. Department of Paediatrics, Paediatric Endocrinology, University Hospital Dresden, Technische Universität Dresden , Dresden 01307 , Germany