title: Community detection of long QT syndrome with a clinical registry: an alternative to ECG screening programs?
abstract: BACKGROUND
  Long QT syndrome (LQTS) prevalence is estimated at 4 of 10,000 based on community electrocardiogram (ECG) screening, about which there is disagreement regarding efficacy, accuracy, cost-effectiveness, and practicality. Family studies of autosomal dominant conditions such as LQTS have revealed 8-9 gene-positive family members per proband.
  
  
  OBJECTIVE
  To evaluate a cardiac/genetic registry and family screening program as a tool to identify LQTS in the community.
  
  
  METHODS
  Possible LQTS probands were referred to the New Zealand Cardiac Inherited Disease service. The registry was first established in the northern region (population 2.03 million), including central Auckland (population 0.46 million). After clinical evaluation, genetic testing and family cascade screening were initiated. Genotype-positive individuals were classified as definite LQTS, and others were classified as definite or probable LQTS by clinical and ECG criteria.
  
  
  RESULTS
  One hundred twelve probands were identified (presentation: 7 sudden death, 82 cardiac event, 16 ECG abnormality, and 7 sudden death of a family member). Following cascade screening, 309 patients with LQTS were identified (248 definite and 61 probable). Two hundred twenty patients had LQTS-causing mutations identified (120 [55%] LQT1, 78 [35%] LQT2, 19 [9%] LQT3, 1 [0.5%] LQT 5, and 2 [1%] LQT7). Thus far, an average of 2.1 definitely or probably affected family members have been identified per proband. The community detection rate is 1.5 of 10,000 for the whole region and 2.2 of 10,000 in Auckland.
  
  
  CONCLUSIONS
  A high level of community detection of LQTS is possible using a clinical registry. With adequate resourcing, this has the potential to be an effective alternative to community ECG screening.
authors.affiliation: Department of Medicine, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand.
authors.forename: Nikki
authors.initials: N
authors.lastname: Earle
authors.forename: Jackie
authors.initials: J
authors.lastname: Crawford
authors.forename: Warren
authors.initials: W
authors.lastname: Smith
authors.forename: Ian
authors.initials: I
authors.lastname: Hayes
authors.forename: Andrew
authors.initials: A
authors.lastname: Shelling
authors.forename: Margaret
authors.initials: M
authors.lastname: Hood
authors.forename: Martin
authors.initials: M
authors.lastname: Stiles
authors.forename: Fraser
authors.initials: F
authors.lastname: Maxwell
authors.forename: David
authors.initials: D
authors.lastname: Heaven
authors.forename: Donald R
authors.initials: DR
authors.lastname: Love
authors.forename: Jonathan R
authors.initials: JR
authors.lastname: Skinner
mesh_terms: D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D002648:Child; D016757:Death, Sudden, Cardiac; D004562:Electrocardiography; D005260:Female; D005820:Genetic Testing / Q000379:methods; D005838:Genotype; D006801:Humans; D015994:Incidence; D008133:Long QT Syndrome / Q000175:diagnosis* / Q000453:epidemiology / Q000235:genetics; D008297:Male; D008403:Mass Screening / Q000379:methods*; D008875:Middle Aged; D009154:Mutation; D009520:New Zealand / Q000453:epidemiology; D012042:Registries; D012111:Residence Characteristics; D017678:Sex Distribution; D016019:Survival Analysis; D055815:Young Adult