title: Prominent QTc prolongation in a patient with a rare variant in the cardiac ryanodine receptor gene.
abstract: We report the case of a 12-year-old female patient with a history of four syncopal episodes related to exercise over 2 years and who showed prominent QTc prolongation on electrocardiogram; therefore, she was clinically diagnosed with long QT syndrome type-1. However, genetic analysis did not identify any LQT-related genes but showed a rare missense variant in the cardiac ryanodine receptor gene. From the results of drug-loading tests, administration of oral propranolol was initiated; thereafter, she experienced no syncopal episodes. This is a case report demonstrating the "overlapping clinical features" of long QT syndrome and catecholaminergic polymorphic ventricular tachycardia.
authors.affiliation: Department of Pediatric Cardiology, Division of Arrhythmias and Electrophysiology, National Cerebral and Cardiovascular Center, 5-7-1 Fujishiro-dai, Suita, 565-8565, Osaka, Japan.|Department of Cardiovascular Medicine, Hyogo Prefectural Kobe Children's Hospital, 1-6-7 chuo-ku, Kobe, 650-0047, Hyogo, Japan.
authors.forename: Yuki
authors.initials: Y
authors.lastname: Taniguchi
authors.affiliation: Department of Pediatric Cardiology, Division of Arrhythmias and Electrophysiology, National Cerebral and Cardiovascular Center, 5-7-1 Fujishiro-dai, Suita, 565-8565, Osaka, Japan. ayamiya@ncvc.go.jp.
authors.forename: Aya
authors.initials: A
authors.lastname: Miyazaki
authors.affiliation: Department of Pediatric Cardiology, Division of Arrhythmias and Electrophysiology, National Cerebral and Cardiovascular Center, 5-7-1 Fujishiro-dai, Suita, 565-8565, Osaka, Japan.
authors.forename: Heima
authors.initials: H
authors.lastname: Sakaguchi
authors.affiliation: Department of Pediatric Cardiology, Division of Arrhythmias and Electrophysiology, National Cerebral and Cardiovascular Center, 5-7-1 Fujishiro-dai, Suita, 565-8565, Osaka, Japan.
authors.forename: Yousuke
authors.initials: Y
authors.lastname: Hayama
authors.affiliation: Department of Pediatric Cardiology, Division of Arrhythmias and Electrophysiology, National Cerebral and Cardiovascular Center, 5-7-1 Fujishiro-dai, Suita, 565-8565, Osaka, Japan.
authors.forename: Norihiro
authors.initials: N
authors.lastname: Ebishima
authors.affiliation: Department of Pediatric Cardiology, Division of Arrhythmias and Electrophysiology, National Cerebral and Cardiovascular Center, 5-7-1 Fujishiro-dai, Suita, 565-8565, Osaka, Japan.
authors.forename: Jun
authors.initials: J
authors.lastname: Negishi
authors.affiliation: Department of Pediatric Cardiology, Division of Arrhythmias and Electrophysiology, National Cerebral and Cardiovascular Center, 5-7-1 Fujishiro-dai, Suita, 565-8565, Osaka, Japan.
authors.forename: Kanae
authors.initials: K
authors.lastname: Noritake
authors.affiliation: Department of Preventive Cardiology, Department of Medicine and Epidemiologic Informatics, Division of Arrhythmias and Electrophysiology, National Cerebral and Cardiovascular Center, 5-7-1 Fujishiro-dai, Suita, 565-8565, Osaka, Japan.
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Miyamoto
authors.affiliation: Department of Cardiovascular Medicine, Division of Arrhythmias and Electrophysiology, National Cerebral and Cardiovascular Center, 5-7-1 Fujishiro-dai, Suita, 565-8565, Osaka, Japan.|Department of Cardiovascular Medicine, Graduate School of Medicine, Nippon Medical School, 1-1-5 Sendagi, Bunkyo-ku, 113-8602, Tokyo, Japan.
authors.forename: Wataru
authors.initials: W
authors.lastname: Shimizu
authors.affiliation: Department of Cardiovascular Medicine, Division of Arrhythmias and Electrophysiology, National Cerebral and Cardiovascular Center, 5-7-1 Fujishiro-dai, Suita, 565-8565, Osaka, Japan.
authors.forename: Takeshi
authors.initials: T
authors.lastname: Aiba
authors.affiliation: Department of Pediatric Cardiology, Division of Arrhythmias and Electrophysiology, National Cerebral and Cardiovascular Center, 5-7-1 Fujishiro-dai, Suita, 565-8565, Osaka, Japan.
authors.forename: Hideo
authors.initials: H
authors.lastname: Ohuchi
mesh_terms: D002648:Child; D004562:Electrocardiography; D005260:Female; D005820:Genetic Testing; D006801:Humans; D008133:Long QT Syndrome / Q000175:diagnosis* / Q000235:genetics*; D020125:Mutation, Missense; D019837:Ryanodine Receptor Calcium Release Channel / Q000235:genetics*; D013575:Syncope / Q000209:etiology; D017180:Tachycardia, Ventricular / Q000175:diagnosis* / Q000235:genetics*; D000098850:Polymorphic Catecholaminergic Ventricular Tachycardia
chemical_list: D019837:Ryanodine Receptor Calcium Release Channel
keywords: Catecholaminergic polymorphic ventricular tachycardia; Long QT syndrome; Premature ventricular conduction; Ryanodine receptor 2 gene