KCNH2 and long QT syndrome 3: Regarding channelopathies, among the most frequently involved genes, SCN5A represents a key gene and is involved in both long QT syndrome type 3 and Brugada syndrome and has been identified in over 20%–25% of SCDY cases with a structurally normal heart but is also responsible for dilated cardiomyopathy.Furthermore, pathogenic variants in KCNQ1 and KCNH2 are responsible for LQT1 and LQT2 forms, RYR2 is implicated in catecholaminergic polymorphic ventricular syndrome, KCNQ1, KCNJ2 and KCNH2 related to short QT syndrome (5).