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Updated: Jul 24, 2026

Isolation and Kv Channel Recordings in Murine Atrial and Ventricular Cardiomyocytes
Published on: March 12, 2013
QT interval is linked to 2 long-QT syndrome loci in normal subjects
A Busjahn1, H Knoblauch, H D Faulhaber
1Franz Volhard Clinic and Max Delbrück Center for Molecular Medicine, Medical Faculty of the Charité, Humboldt University of Berlin, Germany.
Background:
The rate-corrected QT interval (QTc) is heritable, and the discovery of quantitative trait loci that influence the QTc would be an important step in identifying the genes responsible for life-threatening arrhythmias in the general population. We studied 66 pairs of unselected normal dizygotic (DZ) twin subjects and their parents in a sib-pair analysis. We tested for linkage of gene loci harboring genes known to cause the long-QT syndrome (LQT) to the quantitative trait QTc.
Methods And Results:
We found genetic variance on QRS duration, QRS axis, T-wave axis, and QTc. Women had a longer QTc than men. Microsatellite markers were tested in the vicinity of the gene loci for the 5 known LQT genes. We found significant linkage of QTc with the loci for LQT1 on chromosome 11 and LQT4 on chromosome 4 but not to LQT2, LQT3, or LQT5. We also found linkage of the QRS axis with LQT2 and LQT3.
Conclusions:
We suggest that these quantitative trait loci may represent the presence of variations in LQT genes that could be important to the risk for rhythm disturbances in the general population.
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