SCN5A and long QT syndrome 3: Although some particular mutations (NaV1.5-E1784K and NaV1.5-D1790G, also associated with Brugada phenotype) have been related to a better prognosis in LQT3 patients, at present there is not enough evidence supporting that the type and/or location of SCN5A mutations in LQT3 patients have effects on the final phenotype [30].