SCN5A and long QT syndrome 3: The increased persistent Na+ currents in this mouse line mimic observations in humans: gain-of-function sodium voltage-gated channel alpha subunit 5 (SCN5A) genetic variants are associated with patients with lone AF (11), an increased incidence of AF in patients with congenital long QT syndrome type 3 (12), and an increased persistent Na+ current in patients with permanent AF (13).