1. London North Genomic Laboratory, Great Ormond Street NHS Foundation Trust, and Genetics and Genomic MedicineUCL Great Ormond Street Institute of Child Health London UK
2. Department of Obstetrics and GynaecologyUniversity of Melbourne Melbourne Victoria Australia
3. Antenatal Testing CentreInova Alexandria Hospital Alexandria VA
4. Departments of Pathology and Cell BiologyColumbia University New York NY
5. Departments of Obstetrics and GynaecologyUniversity Hospitals Leuven Leuven Belgium
6. Department of Obstetrics and GynaecologyMount Sinai Hospital and University of Toronto Toronto Ontario Canada
7. Eunice Kennedy Shriver National Institute of Child Health and Human DevelopmentNational Institutes of Health Bethesda MD