[1] Univ Groningen, Dept Pediat, Beatrix Childrens Hosp, Univ Med Ctr Groningen, NL-9700 AB Groningen, Netherlands
[2] Canisius Wilhelmina Hosp, Dept Pediat, Nijmegen, Netherlands
[3] Med Ctr Leeuwarden, Dept Pediat, Leeuwarden, Netherlands
[4] Univ Groningen, Univ Med Ctr Groningen, Beatrix Childrens Hosp, Dept Pediat Endocrinol, Groningen, Netherlands