[1] Cambridge Univ Hosp NHS Fdn Trust, Cambridge, England
[2] Univ Southampton, Fac Med, Southampton, Hants, England
[3] Univ Hosp Birmingham NHS Fdn Trust, Birmingham, W Midlands, England
[4] Guys & St Thomas NHS Fdn Trust, London, England
[5] Barts Hlth NHS Trust, Haemophilia Ctr, Royal London Hosp, London, England
[6] Imperial Coll Healthcare NHS Trust, London, England
[7] Imperial Coll London, Ctr Haematol, Dept Immunol & Inflammat, London, England
[8] BioMarin Pharmaceut Inc, Novato, CA USA