title: Response to the Letter to the Editor by Qiuming Hu, Haiping Li, and Xixi Wu.
authors.affiliation: Department of Pediatrics, Pusan National University Hospital, Pusan National University School of Medicine and Biochemical Research Institute, Busan, Korea. Electronic address: pink2129@naver.com.
authors.forename: Young Mi
authors.initials: YM
authors.lastname: Kim
mesh_terms: D005260:Female; D006801:Humans; D008297:Male; D009103:Multiple Sclerosis / Q000453:epidemiology*; D009902:Optic Neuritis / Q000453:epidemiology*