1. Division of Cardiology, Department of Pediatrics, Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada
2. Department of Pediatrics, London Health Sciences Centre, London, Ontario, Canada
3. Department of Pediatrics, Kingston General Hospital, Kingston, Ontario, Canada
4. Department of Pediatrics, Children's Hospital of Eastern Ontario, Ottawa, Ontario, Canada
5. Department of Pediatrics, Hamilton Health Sciences Centre, Hamilton, Ontario, Canada
6. Department of Obstetrics and Gynecology, The Prenatal Diagnosis and Medical Genetics Program, Mount Sinai Hospital, University of Toronto, Toronto, Ontario, Canada