A broad spectrum of mutations in SCN5A were related to a variety of inherited cardiac diseases, such as long QT syndrome type 3 (LQT3), Brugada syndrome (BrS), cardiac conduction disease (CCD), or sick sinus syndrome (SSS) (Zimmer and Surber, 2008; Gui et al., 2010). Here, SCN5A is linked to sick sinus syndrome.