1. Montreal Heart Institute, Montreal, Quebec, Canada;
2. Université de Montréal, Montreal, Quebec, Canada;
3. National Heart, Lung, and Blood Institute, Division of Cardiovascular Sciences, Bethesda, MD;
4. Center for Human Genetics, Department of Medicine, Duke University Medical Center, Durham, NC;
5. Emory University, Atlanta, GA;
6. Division of Hematology, Department of Medicine, Duke University Medical Center, Durham, NC; and
7. Department of Medicine, Sickle Cell Center, Medical College of Georgia, Augusta, GA