1. Medical Genetics Branch; National Human Genome Research Institute; National Institutes of Health; Bethesda Maryland
2. McKusick-Nathans Institute of Genetic Medicine; Johns Hopkins University School of Medicine; Baltimore Maryland
3. Department of Pediatrics; Johns Hopkins University School of Medicine; Baltimore Maryland
4. Department of Pathology; Johns Hopkins University School of Medicine; Baltimore Maryland
5. Cytogenetics and Microarray Laboratory; Kennedy Krieger Institute; Baltimore Maryland