1. Department of HealthClinical Genetic Service Hong Kong
2. Prenatal Diagnostic LaboratoryTsan Yuk Hospital Hong Kong
3. Department of Obstetrics and GynaecologyQueen Mary Hospital Hong Kong
4. Department of Obstetrics and GynaecologyLi Ka Shing Faculty of Medicine, University of Hong Kong Hong Kong HKSAR
5. Department of Paediatrics and Adolescent Medicine, Li Ka Shing Faculty of MedicineUniversity of Hong Kong Hong Kong HKSAR