1. Department of Molecular Physiology and Biophysics, Vanderbilt University Medical Center, Nashville, Tennessee;
2. Division of Diabetes, Endocrinology, and Metabolism, Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee;
3. Center for Human Genetics Research, Department of Biomedical Informatics, Vanderbilt University Medical Center, Nashville, Tennessee; and
4. Veterans Affairs Tennessee Valley Healthcare System, Nashville, Tennessee