[1] Harvard Med Sch, Massachusetts Gen Hosp, Div Hematol, Boston, MA 02115 USA
[2] Harvard Med Sch, Dana Farber Boston Childrens Canc & Blood Disorder, Boston, MA USA
[3] Rigshosp, Dept Hematol, Copenhagen, Denmark
[4] Univ Wurzburg, Dept Pediat, Wurzburg, Germany
[5] Fdn IRCCS Ca Granda Osped Maggiore Policlin, Milan, Italy
[6] CHU Henri Mondor, Unite Malad Genet Globule Rouge, AP HP, Creteil, France
[7] Univ Toronto, Div Hematol, Toronto, ON, Canada
[8] Hammersmith Hosp, Imperial Coll Healthcare NHS Fdn Trust, Dept Immunol & Inflammat, London, England
[9] Hosp Univ La Paz, Hematol Dept, Madrid, Spain
[10] Mahidol Univ, Siriaj Hosp, Dept Pediat, Bangkok, Thailand
[11] Agios Pharmaceut Inc, Cambridge, MA USA
[12] Univ Utrecht, Univ Med Ctr Utrecht, Ctr Benign Hematol Thrombosis & Hemostasis, Van Creveldklin, Utrecht, Netherlands