[1] Univ Duisburg Essen, Univ Hosp Essen, Dept Pediat 3, Pediat Hematol & Oncol, Essen, Germany
[2] Univ Duisburg Essen, Univ Hosp Essen, Dept Pediat 2, Pediat Endocrinol & Diabetol, Essen, Germany
[3] Univ Duisburg Essen, Univ Hosp Essen, Dept Endocrinol Diabet & Metab, Essen, Germany
[4] Ruhr Univ Bochum, Div Rare Dis, Dept Pediat, St Josef Hosp, Bochum, Germany