[1] Univ London, Queen Marys Sch Med, St Bartholomews & Royal London Hosp, Dept Haematol, London E1 2AD, England
[2] Univ Padua, Fac Med, Dept Pediat, Italian Natl Assoc Pediat Haematooncol, Padua, Italy
[3] Galliera Hosp, Inst Human Genet, Genoa, Italy