The increased peak INa due to Scn5a gain-of-function mutation is associated with arrhythmias such as atrial fibrillation, long QT syndrome; polymorphic ventricular complexes, and ventricular arrhythmia (Han et al., 2018; Savio-Galimberti et al., 2018). The gene discussed is SCN5A; the disease is cardiac arrhythmia.