1 Third Department of Internal Medicine, Kagoshima University School of Medicine, 8-35-1 Sakuragaoka, Kagoshima 890-8520, JapanDepartment of Neurology, National Sanatorium Okinawa Hospital, Okinawa, JapanDivision of Molecular Pathology and Genetic Epidemiology, Center for Chronic Viral Diseases, Kagoshima University School of Medicine, Kagoshima, JapanDepartment of Psychiatry and Columbia Genome Center, Columbia University, New York, New York, USA.