Annually thousands of sudden deaths involving young individuals (<35 years of 
age) remain unexplained following a complete medicolegal investigation that 
includes an autopsy. In fact, epidemiological studies have estimated that over 
half of sudden deaths involving previously healthy young individuals have no 
morphological abnormalities identifiable at autopsy. Cardiac channelopathies 
associated with structurally normal hearts such as long QT syndrome (LQTS), 
catecholaminergic polymorphic ventricular tachycardia (CPVT), and Brugada 
syndrome (BrS), leave no evidence to be found at autopsy, leaving investigators 
to only speculate that a lethal arrhythmia might lie at the heart of a sudden 
unexplained death (SUD). In cases of autopsy-negative SUD, continued 
investigation, through the use of a cardiological and genetic evaluation of 
first- or second-degree relatives and/or a molecular autopsy, may pinpoint the 
underlying mechanism attributing to the sudden death and allow for the 
identification of living family members with the pathogenic substrate that 
renders them vulnerable to an increased risk for cardiac events, including 
sudden death.