Although the fundamental mechanisms of each of these SCN5A associated disorders may differ considerably, phenotypic overlap exists, including individuals with both the LQTS and BrS [13] and those with both BrS and conduction system disease.[14] Also, up to 3% of patients with LQTS and 22% with BrS suffer from AF.[15, 16]. Here, SCN5A is linked to atrial fibrillation.