[1] Univ Med Ctr Utrecht, Dept Haematol, Van Creveldklin, Utrecht, Netherlands
[2] Klinikum Bremen Mitte, Prof Hess Childrens Hosp, Bremen, Germany
[3] Univ Munich, Dr von Haunersches Childrens Hosp, Munich, Germany
[4] Great Ormond St Hosp Sick Children, Dept Haematol, Heamophilia Ctr, London WC1N 3JH, England
[5] Lund Univ, Dept Paediat & Coagulat Disorders, Univ Hosp, Malmo, Sweden
[6] Univ Helsinki, Hosp Children & Adolescents, Helsinki, Finland
[7] Giannina Gaslini Childrens Hosp, Thrombosis & Hemostasis Unit, Dept Hematol & Oncol, Genoa, Italy
[8] Our Ladys Childrens Hosp, Dept Haematol Oncol, Dublin, Ireland
[9] Karolinska Univ Hosp, Paediat Dept Coagulat Disorders, Stockholm, Sweden
[10] Univ Med Ctr, Van Creveldklin, Dept Hematol, Utrecht, Netherlands
[11] Univ Med Ctr, Van Creveldklin, Julius Ctr Hlth Sci & Primary Care, Utrecht, Netherlands