Department of Health, Clinical Genetic Service, HKSAR, Hong Kong *Dr. Sze Wing Shirley Cheng is considered as the first author. Received 4 October 2021 Accepted 19 October 2021 Correspondence to Fai Man Ivan Lo, Department of Health, Clinical Genetic Service, HKSAR, Hong Kong, Tel: (+852) 35136508; fax: (+852) 2729 1440; email: [email protected]