1. Department of Pediatrics; Tenshi Hospital; N-12, E-3 Sapporo 065-8611 Japan
2. Department of Obstetrics and Gynecology; Tenshi Hospital; N-12, E-3 Sapporo 065-8611 Japan
3. Department of Pediatric Surgery; Tenshi Hospital; N-12, E-3 Sapporo 065-8611 Japan
4. Department of Pediatrics; Sapporo Hokuyu Hospital; 6-6 Higashi-Sapporo Sapporo 003-0006 Japan
5. Maternity and Perinatal Care Center; Hokkaido University Hospital; N-15, W-7 Sapporo 060-8638 Japan
6. Division of Medical Genetics; Kanagawa Children's Medical Center; 2-138-4 Mutsukawa Minami-ku Yokohama 232-8555 Japan