title: Long QT syndrome with nocturnal cardiac events caused by a KCNH2 missense mutation (G604S).
abstract: An 8-year-old boy suffered from an unconsciousness attack and torsade de pointes arrhythmia during sleep or at rest. His electrocardiogram showed prolonged QT intervals, but the T wave morphology was atypical for type 1, 2 or 3 congenital long-QT syndrome (LQTS). Intravenous epinephrine slightly prolonged the QT interval whereas mexiletine infusion shortened the QT interval. Although these clinical characteristics might suggest type 3 LQTS, a genetic analysis identified the G604S-KCNH2 mutation (type 2 LQTS). Because mismatches between the genotype and phenotype of LQTS are possible, genetic analysis of LQTS is important to identify the most appropriate therapeutic option and risk stratification.
authors: Division of Cardiology, Niigata University Graduate School of Medical and Dental Sciences, Japan.
authors: Akinori
authors: A
authors: Sato
authors: Masaomi
authors: M
authors: Chinushi
authors: Hiroshi
authors: H
authors: Suzuki
authors: Fujito
authors: F
authors: Numano
authors: Takanori
authors: T
authors: Hanyu
authors: Kenichi
authors: K
authors: Iijima
authors: Hiroshi
authors: H
authors: Watanabe
authors: Hiroshi
authors: H
authors: Furushima
mesh_terms: D002648:Child; D000072237:ERG1 Potassium Channel; D004562:Electrocardiography; D004837:Epinephrine; D051638:Ether-A-Go-Go Potassium Channels / Q000235:genetics*; D056726:Genetic Association Studies; D006579:Heterozygote; D006801:Humans; D008133:Long QT Syndrome / Q000150:complications / Q000175:diagnosis / Q000235:genetics* / Q000503:physiopathology; D008297:Male; D008801:Mexiletine; D020125:Mutation, Missense; D012890:Sleep; D016171:Torsades de Pointes / Q000209:etiology / Q000235:genetics / Q000503:physiopathology
chemical_list: D000072237:ERG1 Potassium Channel; D051638:Ether-A-Go-Go Potassium Channels; C000606913:KCNH2 protein, human; D008801:Mexiletine; D004837:Epinephrine