1. From the Bristol Institute for Transfusion Sciences, National Blood Service, Bristol; the Department of Biochemistry, University of Bristol, Bristol, United Kingdom; the Department of Nephrology and Hypertension, Kaplan Medical Center (affiliated to Hebrew University-Hadassah Medical School), Rehovot, Israel; the National Blood Group Reference Laboratory, Magen David Adom, Blood Services Center, Ramat Gan, Israel; and the Evelina Children's Hospital, Guy's and St Thomas' NHS Trust, London, United Kingdom.