title: Mutation screening in KCNQ1, HERG, KCNE1, KCNE2 and SCN5A genes in a long QT syndrome family.
abstract: BACKGROUND
  Long QT syndrome (LQTS), an inherited cardiac arrhythmia, is a disorder of ventricular repolarisation characterised by electrocardiographic abnormalities and the onset of torsades de pointes leading to syncope and sudden death. Genetic polymorphisms in 5 well-characterised cardiac ion channel genes have been identified to be responsible for the disorder. The aim of this study is to identify disease-causing mutations in these candidate genes in a LQTS family.
  
  
  METHODS
  The present study systematically screens the coding region of the LQTS-associated genes (KCNQ1, HERG, KCNE1, KCNE2 and SCN5A) for mutations using DNA sequencing analysis.
  
  
  RESULTS
  The mutational analysis revealed 7 synonymous and 2 non-synonymous polymorphisms in the 5 ion channel genes screened.
  
  
  CONCLUSIONS
  We did not identify any clear identifiable genetic marker causative of LQTS, suggesting the existence of LQTS-associated genes awaiting discovery.
authors.affiliation: Department of Pharmacology, National University of Singapore, Singapore.
authors.forename: Seok-Hwee
authors.initials: SH
authors.lastname: Koo
authors.forename: Wee-Siong
authors.initials: WS
authors.lastname: Teo
authors.forename: Chi-Keong
authors.initials: CK
authors.lastname: Ching
authors.forename: Soh-Ha
authors.initials: SH
authors.lastname: Chan
authors.forename: Edmund J D
authors.initials: EJ
authors.lastname: Lee
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D004252:DNA Mutational Analysis; D000072237:ERG1 Potassium Channel; D051638:Ether-A-Go-Go Potassium Channels / Q000032:analysis / Q000235:genetics*; D005260:Female; D016368:Frameshift Mutation; D006801:Humans; D051657:KCNQ1 Potassium Channel / Q000032:analysis / Q000235:genetics*; D008133:Long QT Syndrome / Q000235:genetics*; D008297:Male; D008875:Middle Aged; D009124:Muscle Proteins / Q000032:analysis / Q000235:genetics*; D062554:NAV1.5 Voltage-Gated Sodium Channel; D011110:Polymorphism, Genetic / Q000235:genetics*; D024642:Potassium Channels, Voltage-Gated / Q000032:analysis / Q000235:genetics*; D015222:Sodium Channels / Q000032:analysis / Q000235:genetics*; D015534:Trans-Activators
chemical_list: D000072237:ERG1 Potassium Channel; D051638:Ether-A-Go-Go Potassium Channels; C489622:KCNE1 protein, human; C489619:KCNE2 protein, human; C000606913:KCNH2 protein, human; D051657:KCNQ1 Potassium Channel; C496909:KCNQ1 protein, human; D009124:Muscle Proteins; D062554:NAV1.5 Voltage-Gated Sodium Channel; D024642:Potassium Channels, Voltage-Gated; C568320:SCN5A protein, human; D015222:Sodium Channels; D015534:Trans-Activators