Cardiac gene defects can cause sudden cardiac death in young people

In Europe, sudden cardiac death (SCD) is one of the most common causes of death. Although sudden cardiac death usually happens in older people, 5% to 10% of the affected individuals are young and apparently healthy. Sudden death in infants, children, and young adults is relatively rare, with an incidence of 1 to 5 per 100 000 persons per year. Nonetheless, up to 7000 asymptomatic children die in the USA each year, almost half of them without any warning signs or symptoms.

Selective literature review.

Although structural cardiovascular abnormalities explain most cases of sudden cardiac death in young people, the cause of death remains unexplained after autopsy in 10% to 30% of cases. Potentially lethal ion channel disorders (channelopathies) such as the long QT syndromes (LQTS), catecholaminergic polymorphic ventricular tachycardia (CPVT), and the Brugada syndrome (BrS) may account for at least one-third of these unexplained cases. Most of these diseases are hereditary with autosomal-dominant transmission, i.e., there is a 50% chance that the children of affected individuals will be affected themselves.

Post-mortem genetic screening for sequence variations in cardiac ion channel genes has become an important forensic tool for elucidating the cause of sudden cardiac death. Moreover, it allows the identification of other family members bearing the previously undiagnosed gene defect, who can then undergo a cardiological evaluation if indicated by their clinical history.