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Updated: Apr 28, 2026

Determining the Likelihood of Variant Pathogenicity Using Amino Acid-level Signal-to-Noise Analysis of Genetic Variation
07:15

Determining the Likelihood of Variant Pathogenicity Using Amino Acid-level Signal-to-Noise Analysis of Genetic Variation

Published on: January 16, 2019

10.2K

Genetics of long QT syndrome

David J Tester1, Michael J Ackerman1

  • 1Mayo Clinic, Rochester, Minnesota.

Methodist Debakey Cardiovascular Journal
|June 17, 2014
PubMed

Insights

Long QT syndrome (LQTS) is a genetic heart condition causing delayed repolarization and increased risk of sudden cardiac death. Genetic testing is crucial but requires careful interpretation of genotype-phenotype correlations.

Area of Science:

  • Cardiology
  • Genetics
  • Molecular Biology

Background:

  • Long QT syndrome (LQTS) is a life-threatening cardiac arrhythmia linked to delayed myocardial repolarization.
  • It increases the risk of torsades des pointes (TdP), syncope, seizures, and sudden cardiac death (SCD).
  • Three major genes (KCNQ1, KCNH2, SCN5A) cause ~75% of LQTS cases, with minor genes accounting for <5%.

Purpose of the Study:

  • To review genotype-phenotype correlations in LQTS.
  • To discuss risk stratification based on specific mutations.
  • To highlight the importance of careful interpretation of genetic testing results.

Main Methods:

  • Review of current literature on LQTS genetics and clinical manifestations.
  • Analysis of genotype-phenotype correlations for major and minor LQTS genes.
  • Discussion of atypical LQTS and syndromic disorders associated with QT prolongation.

Main Results:

  • Major LQTS genotypes show gene-specific triggers, ECG patterns, and therapeutic responses.
  • Intragenic and mutation-specific risk stratification is increasingly feasible.
  • Atypical LQTS syndromes include ankyrin-B, Anderson-Tawil (ATS), and Timothy syndrome (TS).

Conclusions:

  • Genetic testing is recommended for suspected or persistent QT prolongation.
  • Understanding genotype-phenotype correlations aids in risk stratification and management.
  • Careful interpretation of genetic test results is essential for optimal patient care.

Keywords:
geneticsion channellong QT syndrome

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