[1] Univ Frankfurt, Sch Med, Dept Hematol, Frankfurt, Germany
[2] Inst Biomed Res, Frankfurt, Germany
[3] Univ Heidelberg, Inst Human Genet, D-6900 Heidelberg, Germany
[4] German Canc Res Ctr, Div Mol Epidemiol, Heidelberg, Germany
[5] Ctr Mol Pathol, Hannover Med Sch, Hannover, Germany
[6] Univ Heidelberg, Natl Ctr Tumor Dis, D-6900 Heidelberg, Germany
[7] Univ Frankfurt, Sch Med, Dept Pediat Hematol, Frankfurt, Germany
[8] EUFETS AG, Idar Oberstein, Germany
[9] UCL, Inst Child Hlth, London WC1E 6BT, England
[10] Childrens Hosp Zurich, Div Hematol Immunol, Zurich, Switzerland