SCN5A and Brugada syndrome: However, scarce information is available regarding the mechanism of Nav1.5 regulation by telethonin, although physical interaction between TCAP and Nav1.5 was evidenced by co-immunoprecipitation methods and mutations in the telethonin coding gene (TCAP) has been found to alter the channel-gating properties of Nav1.5 in patients with abnormal gut motility and Brugada syndrome [285,286].