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“Long QT Syndrome Type-1”, Victor McKusick, Mendelian Inheritance in Man, 1966. (KCNQ1) I45.81

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Genomic coordinate (human 11:2,445,008 KCNQ1 ).

Cytoband (human 11p15.5 KCNQ1).

Here I present: “Long QT Syndrome Type-1″, Victor McKusick, Mendelian Inheritance in Man’, 1966. (KCNQ1) I45.81

Potassium channels represent the most complex class of voltage-gated ion channels from both functional and structural standpoints. Present in all eukaryotic cells, their diverse functions include maintaining membrane potential, regulating cell volume, and modulating electrical excitability in neurons. The delayed rectifier function of potassium channels allows nerve cells to efficiently repolarize following an action potential.

Potassium voltage-gated channel-Q1 (KCNQ1) is a potassium channel protein encoded in the human by the KCNQ1 gene. Its mutation causes Long QT Syndrome. Kv7.1 is a voltage and lipid-gated potassium channel present in the cell membranes of cardiac tissue and in inner ear neurons among other tissues.

Long QT Syndrome Type-1 (LQT1) is a genetic heart condition caused by mutation in the KCNQ1 gene, which reduces the slow component of the potassium current (I_{Ks}), causing delayed heart muscle repolarization. The primary trigger for arrhythmias, such as torsade de pointes and syncope, is sympathetic nervous system stimulation, particularly exercise and emotional stress, with swimming being a classic trigger.
Key Features of LQT1:
  • Cause: Loss-of-function mutations in the KCNQ1 gene (autosomal dominant).
  • Arrhythmia Triggers: Exertion, specifically swimming, and sudden emotional stress.
  • ECG Findings: Typically characterized by a broadened T-wave.
  • Treatment: LQT1 patients show high responsiveness to \beta-blockers (beta-blockers).


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