[1] Kyushu Univ, Grad Sch Med Sci, Dept Pediat, Higashi Ku, Fukuoka 8128582, Japan
[2] Tohoku Univ, Dept Neurol, Sendai, Miyagi 980, Japan
[3] Tohoku Univ, Dept Hematol & Oncol, Sendai, Miyagi 980, Japan
[4] Tohoku Univ, Dept Clin Pathol, Miyagi Childrens Hosp, Sendai, Miyagi 980, Japan
[5] Tohoku Univ, Dept Pediat Oncol, Inst Dev Aging & Canc, Sendai, Miyagi 980, Japan