1. Department of Medicine, Vanderbilt University, Nashville, TN.
2. Division of Epidemiology, Vanderbilt University, Nashville, TN.
3. Institute for Medicine and Public Health, Vanderbilt University, Nashville, TN.
4. Center for Human Genetics Research, Vanderbilt University, Nashville, TN.
5. Department of Obstetrics and Gynecology, Vanderbilt University, Nashville, TN.
6. Vanderbilt Epidemiology Center, Vanderbilt University, Nashville, TN.