1. Thomas Jefferson University, Cardeza Foundation for Hematologic Research, and the Department of Medicine, Jefferson Medical College, Philadelphia, PA;
2. Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX;
3. Department of Statistics, Rice University, Houston, TX;
4. Puget Sound Blood Center, Seattle, WA;
5. Department of Pharmacology, University of Washington, Seattle, WA;
6. Departments of Epidemiology and Genetics, University of Alabama at Birmingham, Birmingham, AL; and
7. Department of Medicine, Baylor College of Medicine, Houston, TX