1. Departments of Pediatrics and Clinical Genetics, Academic Medical Center; University of Amsterdam; Amsterdam Netherlands
2. National Human Genome Research Institute; National Institutes of Health; Bethesda Maryland
3. Department of Genetics; Children's Hospital of Eastern Ontario; Ottawa Canada
4. Departments of Medical Genetics and Pediatrics; University of British Columbia and BC Children's Hospital; Vancouver British Columbia Canada
5. Division of Medical Genetics, Human Genetics; Pathology; Obstetrics and Gynecology; University of Utah; Salt Lake City Utah
6. Faculty of Medicine, University of Southampton and Wessex Clinical Genetics Service; University Hospital Southampton; Southampton United Kingdom