[1] Univ Med Ctr Utrecht, Utrecht, Netherlands
[2] Univ Minnesota, Minneapolis, MN USA
[3] Duke Univ, Med Ctr, Pediat BMT Program, Durham, NC USA
[4] Royal Manchester Childrens Hosp, Manchester M27 1HA, Lancs, England
[5] Our Ladys Hosp Sick Children, Dublin, Ireland
[6] Great Ormond St Hosp Sick Children, London WC1N 3JH, England
[7] Hop Univ Necker Enfants Malad, Paris, France
[8] San Gerardo Univ Hosp, Monza, Italy
[9] Univ Hosp Gasthuisberg, B-3000 Louvain, Belgium
[10] Ghent Univ Hosp, Ghent, Belgium
[11] Univ Pittsburgh, Pittsburgh, PA USA
[12] Univ Med Ctr Groningen, NL-9713 AV Groningen, Netherlands
[13] Univ Med Ctr Utrecht, Blood & Marrow Transplantat Program, Utrecht, Netherlands