[1] Univ Freiburg, Dept Gen Pediat Adolescent Med & Neonatol, Med Ctr, Fac Med, D-79106 Freiburg, Germany
[2] Univ Childrens Hosp Regensburg, Dept Pediat, St Hedwigs Campus, D-93049 Regensburg, Germany
[3] Univ Freiburg, Dept Gen Pediat Adolescent Med & Neonatol, Lab Clin Biochem & Metab, Fac Med,Med Ctr, D-79106 Freiburg, Germany