Mutations in KCND3 are associated with Brugada syndrome. Depicted are A, DHPLC profiles (normal, red trace and abnormal, green trace) and B, DNA sequencing chromatograms. C, Predicted protein topology schematic of Kv4.3 indicating the location of the L450F and G600R mutations. D, Sequence conservation across species for the L450F and G600R mutations.