Learn More
OBJECTIVES This study aims to address whether D85N, a KCNE1 polymorphism, is a gene variant that causes long QT syndrome (LQTS) phenotype. BACKGROUND KCNE1 encodes the beta-subunit of cardiac voltage-gated K(+) channels and causes LQTS, which is characterized by the prolongation of the QT interval and torsades de pointes, a lethal arrhythmia. D85N, a(More)
OBJECTIVES We carried out a complete screening of the SCN5A gene in 38 Japanese patients with Brugada syndrome to investigate the genotype-phenotype relationship. BACKGROUND The gene SCN5A encodes the pore-forming alpha-subunit of voltage-gated cardiac sodium (Na) channel, which plays an important role in heart excitation/contraction. Mutations of SCN5A(More)
OBJECTIVES This study describes a novel heterozygous gain-of-function mutation in the cardiac sodium (Na+) channel gene, SCN5A, identified in a Japanese family with lone atrial fibrillation (AF). BACKGROUND SCN5A mutations have been associated with a variety of inherited arrhythmias, but the gain-of-function type modulation in SCN5A is associated with(More)
BACKGROUND Drugs with I(Kr)-blocking action cause secondary long-QT syndrome. Several cases have been associated with mutations of genes coding cardiac ion channels, but their frequency among patients affected by drug-induced long-QT syndrome (dLQTS) and the resultant molecular effects remain unknown. METHODS AND RESULTS Genetic testing was carried out(More)
AIMS We aimed to examine the validity of heart rate (HR) at rest before β-blocker therapy as a risk factor influencing cardiac events (ventricular fibrillation, torsades de pointes, or syncope) in long QT type 2 (LQT2) patients. METHODS AND RESULTS In 110 genetically confirmed LQT2 patients (45 probands), we examined the significance of variables [HR at(More)
BACKGROUND In the short- to mid-term, cardiomyocytes generated from human-induced pluripotent stem cells (hiPSC-CMs) have been reported to be less mature than those of adult hearts. However, the maturation process in a long-term culture remains unknown. METHODS AND RESULTS A hiPSC clone generated from a healthy control was differentiated into CMs through(More)
INTRODUCTION Beta-blockers are widely used to prevent the lethal cardiac events associated with the long QT syndrome (LQTS), especially in KCNQ1-related LQTS (LQT1) patients. Some LQT1 patients, however, are refractory to this therapy. METHODS AND RESULTS Eighteen symptomatic LQTS patients (12 families) were genetically diagnosed as having heterozygous(More)
AIMS CACNA1C mutations have been reported to cause LQTS type 8 (LQT8; Timothy syndrome), which exhibits severe phenotypes, although the frequency of patients with LQT8 exhibiting only QT prolongation is unknown. This study aimed to elucidate the frequency of CACNA1C mutations in patients with long QT syndrome (LQTS), except those with Timothy syndrome and(More)
AIMS Ryanodine receptor gene (RYR2) mutations are well known to cause catecholaminergic polymorphic ventricular tachycardia (CPVT). Recently, RYR2 exon 3 deletion has been identified in patients with dilated cardiomyopathy (DCM) and/or CPVT. This study aimed to screen for the RYR2 exon 3 deletion in CPVT probands, characterize its clinical pathology, and(More)