1. From the Greenwood Genetic Center, Greenwood, South Carolina;
2. Fullerton Genetics, Asheville, North Carolina;
3. Department of Pediatrics, Medical University of South Carolina, Charleston, South Carolina;
4. Department of Obstetrics and Gynecology, University of South Carolina School of Medicine, Columbia, South Carolina; and
5. Department of Epidemiology and Biostatistics, University of South Carolina School of Public Health, Columbia, South Carolina.