1. Department of Haematology, Addenbrooke’s Hospital, Cambridge, Cambridgeshire, UK;
2. Medical Research Council (MRC) Molecular Haematology Unit, Weatherall Institute for Molecular Medicine, John Radliffe Hospital, Headley Way, Headington, Oxford, Oxfordshire, UK;
3. National Haemoglobinopathy Reference Laboratory, Oxford University NHS Foundation Trust, Level 4, John Radcliffe Hospital, Headley Way, Headington, Oxford, Oxfordshire, UK