1. Division of Diabetes, Metabolism and Endocrinology, Showa University Fujigaoka Hospital, Kanagawa 227-8501, Japan
2. Department of Pediatrics, Keio University School of Medicine, Tokyo 160-8582, Japan
3. Division of Diabetes and Endocrinology, Department of Internal Medicine, Showa University School of Medicine, Tokyo 142-8555, Japan
4. Department of Molecular Endocrinology, National Research Institute for Child Health and Development, Tokyo 157-8535, Japan