LAUSR

The voltage-gated sodium (NaV ) channel is required for cardiomyocyte function. In heart, its major, pore-forming, α-subunit is NaV 1.5, encoded by SCN5A, which maps to chromosome 3p21. The NaV channel plays a key role in myocardial excitability, since it is responsible for generating the rising phase of the cardiac action potential. NaV 1.5 often shows alterations in inherited channelopathies causing cardiac arrhythmias. Two well-known arrhythmias in which pathogenic variants of NaV 1.5 are implicated are Brugada syndrome (BrS) and Long QT syndrome (LQTS) type 3 (LQT3), which are due, respectively, to loss- and gain-of-function of the channel1 .