1. Department of Pediatric Kidney, Liver and Metabolic Diseases, Hannover Medical School , Hannover 30625 , Germany
2. Department of Pediatrics, Faculty of Medicine and University Hospital Cologne, University of Cologne , Cologne 50937 , Germany
3. Department of General Pediatrics, Pediatric Nephrology, University Children's Hospital , Münster 48149 , Germany
4. Division of Pediatric Endocrinology and Diabetes, Department of Pediatrics and Adolescent Medicine, University of Lübeck , Lübeck 23562 , Germany
5. University Children's Hospital , Jena 07743 , Germany
6. Division of Pediatric Nephrology, Center for Pediatric and Adolescent Medicine, University Hospital Heidelberg , Heidelberg 69120 , Germany
7. Asklepios Children's Hospital Hamburg-Heidberg , Hamburg-Heidberg 22417 , Germany
8. University Children's Hospital , Mainz 55131 , Germany
9. University Children's Hospital Bochum , Bochum 44892 , Germany
10. St. Elisabeth and St. Barbara Children's Hospital , Halle/Saale 06110 , Germany
11. Christliches Kinderhospital Osnabrück , Osnabrück 49074 , Germany
12. University Children's Hospital Augsburg , Augsburg 86156 , Germany
13. Children's Hospital, Sana Klinikum Lichtenberg , Berlin Lichtenberg 10365 , Germany
14. Kinderkrankenhaus auf der Bult , Hannover 30173 , Germany
15. University Children's Hospital Greifswald , Greifswald 17475 , Germany
16. University Children's Hospital, Evangelisches Klinikum Bethel , Bielefeld 33617 , Germany
17. Clinic for Pediatric Nephrology Hirschaid , Hirschaid 96114 , Germany
18. University Children's Hospital Rostock , Rostock 18057 , Germany
19. Department of General Pediatrics and Hematology/Oncology, University Children's Hospital, University Hospital Tübingen , Tübingen 72076 , Germany
20. Department of Pediatrics and Adolescent Medicine, University Medical Center Göttingen , Göttingen 37075 , Germany
21. Center for Chronically Sick Children, Pediatric Endocrinology, University Medicine , Charité, Berlin 13353 , Germany