[1] Kyushu Univ, Dept Paediat, Grad Sch Med Sci, Higashi Ku, Fukuoka 8128582, Japan
[2] Naha Prefectural Hosp, Div Paediat, Naha, Japan
[3] Natl S Fukuoka Hosp, Div Paediat, Fukuoka, Japan
[4] Kyushu Natl Canc Ctr, Dept Clin Res, Inst Clin Res, Fukuoka, Japan
[5] Kyushu Univ Hosp, Dept Med Informat Sci, Fukuoka, Japan