OBJECTIVE: To explore the clinical and genetic characteristics of five children with Catecholaminergic polymorphic ventricular tachycardia (CPVT). METHODS: Five children with clinical manifestations consistent with CPVT admitted to the Department of Cardiology of Children's Hospital Affiliated to Zhengzhou University from November 2019 to November 2021 were selected as the study subjects. Their clinical data were collected. Potential variants were detected by whole exome sequencing, and Sanger sequencing was used to verify the candidate variants. All patients were treated with β-blocker propranolol and followed up. RESULTS: All patients had developed the disease during exercise and presented with syncope as the initial clinical manifestation. Electrocardiogram showed sinus bradycardia. The first onset age of the 5 patients were (10.4 ± 2.19) years, and the time of delayed diagnosis was (1.6 ± 2.19) years. All of the children were found to harbor de novo heterozygous missense variants of the RYR2 gene, including c.6916G>A (p.V2306I), c.527G>C (p.R176P), c.12271G>A (p.A4091T), c.506G>T (p.R169L) and c.6817G>A (p.G2273R). Among these, c.527G>C (p.R176P) and c.6817G>A (p.G2273R) were unreported previously. Based on the guidelines from the American College of Medical Genetics and Genomics (ACMG), the c.527G>C (p.R176P) was classified as a pathogenic variant (PS2+PM1+PM2_Supporting+PM5+PP3+PP4), and the c.6817G>A (p.G2273R) was classified as a likely pathogenic variant (PS2+PM2_Supporting+PP3+PP4). The symptoms of all children were significantly improved with the propranolol treatment, and none has developed syncope during the follow up. CONCLUSION Discovery of the c.527G>C (p.R176P) and c.6817G>A (p.G2273R) variants has expanded the mutational spectrum of the RYR2 gene. Genetic testing of CPVT patients can clarify the cause of the disease and provide a reference for their genetic counseling.
Child ; Humans ; Mutation ; Propranolol ; Ryanodine Receptor Calcium Release Channel/genetics* ; Syncope ; Tachycardia, Ventricular/diagnosis* ; United States

Humans ; Cardiomyopathy, Hypertrophic/genetics* ; Mutation ; Phenotype ; Ryanodine Receptor Calcium Release Channel/genetics* ; Tachycardia, Ventricular/genetics*

Humans ; Cardiomyopathy, Hypertrophic/genetics* ; Mutation ; Phenotype ; Ryanodine Receptor Calcium Release Channel/genetics* ; Tachycardia, Ventricular/genetics*

Andersen Syndrome/genetics* ; Humans ; Syncope ; Tachycardia, Ventricular

Electrocardiography ; Humans ; Mutation ; Phosphorylation ; Ryanodine Receptor Calcium Release Channel/genetics* ; Tachycardia, Ventricular/genetics*

Adolescent ; Calsequestrin ; genetics ; Child ; Child, Preschool ; China ; Diagnostic Errors ; Female ; Humans ; Male ; Tachycardia, Ventricular ; diagnosis

No abstract available.
Adolescent ; Adrenergic beta-Antagonists/therapeutic use ; Calcium Channel Blockers/therapeutic use ; Cardiomyopathy, Hypertrophic, Familial/complications/genetics/*pathology/physiopathology/therapy ; Electric Countershock ; Electrocardiography ; Female ; Genetic Predisposition to Disease ; Heart Failure/etiology/therapy ; Heart Septum/drug effects/*pathology/physiopathology/ultrasonography ; Humans ; Magnetic Resonance Imaging ; Male ; Middle Aged ; Pedigree ; Phenotype ; Tachycardia, Ventricular/etiology/therapy ; Treatment Outcome ; Ventricular Outflow Obstruction/etiology

Mutation or common intronic variants in cardiac ion channel genes have been suggested to be associated with sudden cardiac death caused by idiopathic ventricular tachyarrhythmia. This study aimed to find mutations in cardiac ion channel genes of Korean sudden cardiac arrest patients with structurally normal heart and to verify association between common genetic variation in cardiac ion channel and sudden cardiac arrest by idiopathic ventricular tachyarrhythmia in Koreans. Study participants were Korean survivors of sudden cardiac arrest caused by idiopathic ventricular tachycardia or fibrillation. All coding exons of the SCN5A, KCNQ1, and KCNH2 genes were analyzed by Sanger sequencing. Fifteen survivors of sudden cardiac arrest were included. Three male patients had mutations in SCN5A gene and none in KCNQ1 and KCNH2 genes. Intronic variant (rs2283222) in KCNQ1 gene showed significant association with sudden cardiac arrest (OR 4.05). Four male sudden cardiac arrest survivors had intronic variant (rs11720524) in SCN5A gene. None of female survivors of sudden cardiac arrest had SCN5A gene mutations despite similar frequencies of intronic variants between males and females in 55 normal controls. Common intronic variant in KCNQ1 gene is associated with sudden cardiac arrest caused by idiopathic ventricular tachyarrhythmia in Koreans.
Adolescent ; Adult ; Aged ; Arrhythmias, Cardiac/genetics ; *Death, Sudden, Cardiac ; Ether-A-Go-Go Potassium Channels/genetics ; Female ; Genetic Markers ; Genetic Predisposition to Disease ; Genetic Variation ; Heart/physiology ; Heart Conduction System/abnormalities ; Humans ; KCNQ1 Potassium Channel/*genetics ; Male ; Middle Aged ; NAV1.5 Voltage-Gated Sodium Channel/*genetics ; Republic of Korea ; Tachycardia, Ventricular/*genetics ; Ventricular Fibrillation/*genetics ; Young Adult

Patients with long QT syndrome can sometimes present with a ventricular fibrillation (VF) storm. Catheter ablation of culprit premature ventricular complexes responsible for the triggering of the VF episodes may be required in rare cases of electrical storm that do not respond to conventional measures, and this can be life-saving. We describe a case of emergency catheter ablation in a young woman with a normal corrected QT interval, who presented with malignant VF storm for the first time. We also discuss the diagnostic and management challenges involved, as well as the value of genetic testing in refining the diagnosis.
Cardiology ; Catheter Ablation ; methods ; Electrocardiography ; methods ; Female ; Heart Arrest ; genetics ; therapy ; Heterozygote ; Humans ; Long QT Syndrome ; genetics ; Tachycardia, Ventricular ; therapy ; Treatment Outcome ; Ventricular Fibrillation ; therapy ; Ventricular Premature Complexes ; genetics ; therapy ; Young Adult

Humans ; Tachycardia, Ventricular ; genetics