Naka Saito1, Hideaki Ueda2, Yasuhiro Ichikawa2. 1. Department of Clinical Laboratory, Kanagawa Children's Medical Center, 2-138-4 Mutsukawa, Minamiku, Yokohama, Kanagawa, 232-8555, Japan. naka.s.n.5@gmail.com. 2. Department of Pediatric Cardiology, Kanagawa Children's Medical Center, Yokohama, Kanagawa, Japan.