1 Division of Hematology, Department of Medicine, Albert Einstein College of Medicine/Montefiore Medical Center, Bronx, New York, USA.
2 Department of Laboratory Medicine, Boston Children's Hospital, Boston, Massachusetts, USA.
3 Department of Pathology, Harvard Medical School, Boston, Massachusetts, USA.
4 Division of Hematology and Medical Oncology, Department of Medicine, Center of Excellence for Sickle Cell Disease, Boston University School of Medicine and Boston Medical Center, Boston, Massachusetts, USA.