1. Institute of Genetic Medicine and Howard Hughes Medical Institute, Johns Hopkins University School of Medicine, Broadway Research Building, Room 539, 733 North Broadway, Baltimore, MD 21205, USA.
2. Center for Medical Genetics, Ghent University Hospital, Ghent 9000, Belgium.
3. Mayo Clinic, Jacksonville, FL 55905, USA.
4. Department of Biochemistry, University of Oxford, Oxford OX1 3QU, UK.
5. Northern Ireland Regional Genetics Centre, Belfast City Hospital, Belfast BT9 7AB, Ireland.
6. Nuffield Department of Obstetrics and Gynaecology, John Radcliffe Hospital, Headington OX3 9DU, UK.
7. Cardiovascular Genetics, GeneDx, Gaithersburg, MD 20877, USA.
8. Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA.
9. McGill University, Montreal, Quebec H3A 2K6, Canada.
10. Shriners Hospital for Children, Portland, OR 97239, USA.