SCN5A and cardiac arrhythmia: We deem this to be unlikely, though, given that patients with mutations in the Nav1.5 AnkG binding domain (and disrupted trafficking of Nav1.5 to the ICD) develop arrhythmias (Brugada syndrome) but not cardiomyopathies (Mohler et al., 2004), which would be expected to occur if structural disorder of the ICD occurred.