title: Genotype and severity of long QT syndrome.
abstract: OBJECTIVE
  To describe the state of the art of our understanding of the long QT syndromes and to provide the genetic correlation of clinical severity of patients with this disorder.
  
  
  METHODS
  In this review, we outline data that were obtained from work in our laboratory, as well as information reported in the literature.
  
  
  METHODS
  The information in this review spans the last decade; data were obtained from the studies that had the most impact, as well as from recent work at our laboratory.
  
  
  METHODS
  The data reported herein were extracted from the world literature on sudden death and the clinical aspects of long QT syndrome. The genes identified to date, mutations in these genes, and the biophysical perturbations in the mutated ion channels, as well as the severity of disease, are detailed.
  
  
  RESULTS
  The extracted data are described as a state-of-the-art review.
  
  
  CONCLUSIONS
  The long QT syndromes, genetically heterogeneous disorders due to mutations in genes encoding ion channels, are relatively common causes of syncope and sudden death. The affected genes, along with the genetic background of individuals, determine the clinical severity of disease. An understanding of the mechanisms responsible for long QT syndrome is expected to enable development of specific therapies.
authors.affiliation: Department of Pediatrics, Texas Children's Hospital and Baylor College of Medicine, Houston 77030, USA.
authors.forename: J A
authors.initials: JA
authors.lastname: Towbin
authors.forename: Z
authors.initials: Z
authors.lastname: Wang
authors.forename: H
authors.initials: H
authors.lastname: Li
mesh_terms: D027682:Cation Transport Proteins; D002874:Chromosome Mapping; D004268:DNA-Binding Proteins; D000072237:ERG1 Potassium Channel; D004562:Electrocardiography; D051638:Ether-A-Go-Go Potassium Channels; D005799:Genes, Dominant; D005808:Genes, Recessive; D005838:Genotype; D006801:Humans; D051656:KCNQ Potassium Channels; D051657:KCNQ1 Potassium Channel; D008133:Long QT Syndrome / Q000175:diagnosis / Q000235:genetics* / Q000503:physiopathology; D009154:Mutation; D062554:NAV1.5 Voltage-Gated Sodium Channel; D010641:Phenotype; D015221:Potassium Channels / Q000235:genetics; D024642:Potassium Channels, Voltage-Gated; D015222:Sodium Channels / Q000235:genetics; D015534:Trans-Activators; D000071230:Transcriptional Regulator ERG
chemical_list: D027682:Cation Transport Proteins; D004268:DNA-Binding Proteins; C072312:ERG protein, human; D000072237:ERG1 Potassium Channel; D051638:Ether-A-Go-Go Potassium Channels; C092509:KCNH6 protein, human; D051656:KCNQ Potassium Channels; D051657:KCNQ1 Potassium Channel; C496909:KCNQ1 protein, human; D062554:NAV1.5 Voltage-Gated Sodium Channel; D015221:Potassium Channels; D024642:Potassium Channels, Voltage-Gated; C568320:SCN5A protein, human; D015222:Sodium Channels; D015534:Trans-Activators; D000071230:Transcriptional Regulator ERG; C059983:potassium channel protein I(sk)