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Genetic association study of QT interval highlights role for calcium signaling pathways in myocardial repolarization

Dan E Arking1, Sara L Pulit2, Lia Crotti3

  • 11] Center for Complex Disease Genomics, McKusick-Nathans Institute of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA. [2].

Nature Genetics
|June 23, 2014
PubMed

Insights

Researchers identified 35 genetic loci linked to the QT interval, a measure of heart repolarization. This discovery enhances understanding of cardiac electrophysiology and identifies potential genes for arrhythmias and sudden cardiac death.

Area of Science:

  • Genetics
  • Cardiology
  • Molecular Biology

Background:

  • The QT interval reflects myocardial repolarization and is heritable.
  • QT prolongation is a risk factor for ventricular arrhythmias and sudden cardiac death (SCD), potentially indicating long-QT syndrome (LQTS).

Purpose of the Study:

  • To identify genetic loci associated with QT interval variation using a large-scale genome-wide association study.
  • To investigate the role of rare variants in LQTS and identify novel candidate genes.

Main Methods:

  • Genome-wide association and replication study in up to 100,000 individuals.
  • Analysis of common variant loci associated with QT interval.
  • Rare variant analysis in LQTS probands and controls.
  • Integration of association, expression, and protein-protein interaction data.

Main Results:

  • Identified 35 common variant loci associated with QT interval, explaining 8-10% of its variation.
  • Highlighted the role of calcium regulation in myocardial repolarization.
  • Identified coding variants in 6 new loci in LQTS probands, requiring further validation.
  • Discovered interactions between newly identified proteins and known repolarization proteins.

Conclusions:

  • Genetic factors significantly influence the QT interval, impacting cardiac electrophysiology.
  • New candidate genes for ventricular arrhythmias, LQTS, and SCD have been identified.
  • The study provides novel insights into the genetic architecture of cardiac repolarization.

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