1 Department of Pediatrics, Chang Gung Memorial Hospital, Keelung, Taiwan; Department of Pediatrics, Chang Gung University, Taoyuan, Taiwan.
2 Department of Pediatrics, Chang Gung University, Taoyuan, Taiwan; Department of Pediatrics, Chang Gung Memorial Hospital and Chang Gung University, Taoyuan, Taiwan. Electronic address: kpm104@cgmh.org.tw.