1 Department of Paediatrics and Adolescent Medicine, The University of Hong Kong, Hong Kong, People's Republic of China. apyliu@hku.hk.
2 Department of Paediatrics and Adolescent Medicine, Hong Kong Children's Hospital, Hong Kong, People's Republic of China. apyliu@hku.hk.
3 Department of Anatomical and Cellular Pathology, Prince of Wales Hospital, The Chinese University of Hong Kong, Hong Kong, People's Republic of China.
4 Department of Paediatrics and Adolescent Medicine, The University of Hong Kong, Hong Kong, People's Republic of China.
5 Department of Paediatrics and Adolescent Medicine, Hong Kong Children's Hospital, Hong Kong, People's Republic of China.
6 Department of Paediatrics, The Chinese University of Hong Kong, Hong Kong, People's Republic of China.
7 Division of Neurosurgery, Prince of Wales Hospital, Hong Kong, People's Republic of China.