[1] Tokyo Med & Dent Univ, Dept Pediat, Shinjuku Ku, Tokyo 1600023, Japan
[2] Natl Ctr Neurol & Psychiat, Natl Inst Neurosci, Dept Neuromuscular Res, Tokyo, Japan
[3] Okayama Univ Hosp, Dept Child Neurol, Okayama, Japan
[4] Kyoto Univ, Grad Sch Med, Dept Biomed Eth, Kyoto, Japan