@misc{oai:niigata-u.repo.nii.ac.jp:00005423,
 author = {Hasegawa, Kanae},
 month = {Mar},
 note = {Background: Atrial fibrillation (AF) is one of the most common cardiac arrhythmias, and in some patients, the disease is inheritable. Hereditary aspects of AF, however, remain not fully elucidated. Objective: The purpose of this study was to identify genetic backgrounds contributed to juvenile-onset AF and to define the mechanism. Methods: In 30 consecutive juvenile-onset AF patients (onset age <50 year-old), we screened AF-related genes (KCNQ1, KCNH2, KCNE1-3 and 5, KCNJ2, and SCN5A). We analyzed the function of mutant channels using whole-cell patch-clamp techniques and computer simulations. Results: Among the juvenile-onset AF patients, we identified three mutations (10%), SCN5A-M1875T, KCNJ2-M301K, and KCNQ1-G229D. Since KCNQ1 variant (G229) identified in a 16-year-old boy was novel, we focused on the proband. The G229D-IKs was found to induce a large instantaneous activating component without deactivation after repolarization to –50 mV. In addition, WT/G229D-IKs (WT and mutant co-expression) displayed both instantaneous and time-dependent activating currents. Compared to WT-IKs, the tail current densities in WT/G229D-IKs were larger at test potentials between –130 and –40 mV, but smaller at test potentials between 20 and 50 mV. Moreover, WT/G229D-IKs resulted in a negative voltage shift for current activation (−35.2 mV) and slower deactivation. WT/G229D-IKs conducted a large outward current Hasegawa et al. A novel KCNQ1 mutation in Juvenile-Onset AF 4 induced by an atrial action potential waveform, and computer simulation incorporating the WT/G229D-IKs results revealed that the mutation shortened atrial but not ventricular action potential. Conclusion: A novel KCNQ1-G229D mutation identified in a juvenile-onset AF patient altered the IKs activity and kinetics, thereby increasing the arrhythmogenicity to AF., 学位の種類: 博士（医学）. 報告番号: 甲第3861号. 学位記番号: 新大院博（医）甲第601号. 学位授与年月日: 平成26年3月24日, Heart Rhythm. 2014, 11(1), 67-75, 新大院博（医）甲第601号},
 title = {A Novel KCNQ1 Missense Mutation Identified in a Patient with Juvenile-Onset Atrial Fibrillation Causes Constitutively Open IKs Channels},
 year = {2014}
}