[1] Inst Canc Res, Sect Haemato Oncol, Sutton, Surrey, England
[2] Univ Milan Biocca, M Tettamanti Res Ctr, Pediat Clin, Monza, Italy
[3] Univ Southampton, Wessex Reg Genet Lab, Salisbury, Wilts, England
[4] Univ Catania, Azienda Policlin, Ctr Pediat Hematol Oncol, I-95124 Catania, Italy