[1] Seoul Natl Univ, Coll Med, Div Pediat Neurol, Dept Pediat,Pediat Clin Neurosci Ctr,Childrens Ho, Seoul 110744, South Korea
[2] Seoul Natl Univ, Coll Med, Dept Pediat, Seoul 110744, South Korea
[3] Sungkyunkwan Univ, Sch Med, Samsung Med Ctr, Dept Pediat, Seoul, South Korea
[4] Sungkyunkwan Univ, Sch Med, Samsung Med Ctr, Dept Lab Med & Genet, Seoul, South Korea