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Updated: Aug 25, 2026

Determining the Likelihood of Variant Pathogenicity Using Amino Acid-level Signal-to-Noise Analysis of Genetic Variation
Published on: January 16, 2019
Genotype-specific clinical manifestation in long QT syndrome
1Division of Cardiology, Department of Internal Medicine, National Cardiovascular Center, 5-7-1 Fujishiro-dai, Suita, Osaka, 565-8565 Japan. wshimizu@hsp.ncvc.go.jp
Abstract:
The congenital form of long QT syndrome (LQTS) is characterized by QT prolongation in the electrocardiogram (ECG) and a polymorphic ventricular tachycardia, Torsade de Pointes (TdP) mainly as a result of an increased sympathetic tone during exercise or mental stress. Recent genetic studies have so far identified seven forms of congenital LQTS caused by mutations in genes of the potassium and sodium channels or membrane adapter located on chromosomes 3, 4, 7, 11, 17 and 21. It is of particular importance to examine the genotype-phenotype correlation, especially in the LQT1, LQT2 and LQT3 forms of LQTS, which make up more than 90% of genotyped patients with LQTS, because it would enable us to manage and treat genotyped patients more effectively.
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