SCN5A and Brugada syndrome: Furthermore, DNA sequencing of patients with Brugada Syndrome, a type of arrhythmia caused by mutations in SCN5A (which encodes Nav1.5), found that substitution of a highly conserved glutamic acid with lysine (E1053K) in the ankyrin binding motif in the DII-III loop of Nav1.5 channels causes loss of AnkG binding and the subsequent failure of localization of Nav1.5 channels to the membrane of cardiomyocytes [25,93].