1. Department of Paediatric Endocrinology (B.K., H.B., V.F., A.G., H.K.), University Children's Hospital, Charité, Humboldt University, D-13353 Berlin, Germany
2. Department of Paediatric Nephrology (J.G.), University Children's Hospital, Charité, Humboldt University, D-13353 Berlin, Germany
3. Children's Hospital (R.F.M.), Philipps University, D-35033 Marburg, Germany
4. Department of Paediatric Nephrology (M.P.), Albert-Ludwigs University, D-79106 Freiburg, Germany
5. Department of Human Genetics (P.W.), University of Münster, D-48149 Münster, Germany
6. Division of Paediatric Endocrinology (O.H.), Department of Paediatrics, University of Lübeck, D-23538 Lübeck, Germany