Yuta Onuki1,2, Shuichiro Fujinaga3. 1. Division of Nephrology, Saitama Children's Medical Center, 1-2 Shintoshin, Chuo-ku, Saitama, Saitama, 330-8777, Japan. 2. Children's Medical Center, Showa University Northern Yokohama Hospital, Yokohama, Kanagawa, Japan. 3. Division of Nephrology, Saitama Children's Medical Center, 1-2 Shintoshin, Chuo-ku, Saitama, Saitama, 330-8777, Japan. f_shuich@d2.dion.ne.jp.