1 Department of Eugenics, Hainan Provincial Public Service Center of Prenatal and Postnatal Care, Haikou, Hainan 570203, China.
2 Department of Medical Genetics, School of Basic Medical Sciences, Southern Medical University, Guangzhou, Guangdong 510515, China.
3 Department of Clinical Laboratory, Hainan Provincial Public Service Center of Prenatal and Postnatal Care, Haikou, Hainan 570203, China.
4 Danzhou Family Planning Service Center, Danzhou, Hainan 571799, China.
5 Department of Medical Genetics, School of Basic Medical Sciences, Southern Medical University, Guangzhou, Guangdong 510515, China; Department of Laboratory Medicine, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong 510515, China. Electronic address: zhouwanjun72@163.com.