[1] Erasmus MC Sophia Childrens Hosp, Dept Pediat Oncol Hematol, Rotterdam, Netherlands
[2] Erasmus Univ, Med Ctr, Dept Clin Genet, Rotterdam, Netherlands
[3] DCOG, The Hague, Netherlands
[4] Univ Med Ctr Hamburg Eppendorf, German Cooperat Study Grp Childhood Acute Lymphob, Eppendorf, Germany
[5] Princess Maxima Ctr Pediat Oncol, Utrecht, Netherlands