In Young People, Sudden Cardiac Death can be Caused by Gene Defects

Researchers from Germany’s Institute for Forensic Medicine have discovered that ion channel disorders like long QT syndromes, catecholaminergic polymorphic ventricular tachycardia, and the Brugada syndrome may account for one-third of unexplainable sudden cardiac death (SCD) in young people.

The researchers subcategorized cardiac gene defects into two groups: disorders that are accompanied by structural cardiovascular abnormalities, such as arrhythmogenic right ventricular dysplasia and hypertrophic cardiomyopathy; and disorders that do not have cardiac changes detectable at the time of death with a cause that is mostly arrhythmogenic, like the ion channels responsible for one-third of the SCD cases in young people.

The team of researchers found that post-mortem genetic screening for the presence of sequence variations in cardiac ion channel genes was helpful in ascertaining the cause of SCD in otherwise unclear cases.

SCD is listed as one of the most common causes of death in Europe, and although it usually happens among older people, 5-10% of cases there occur in young and apparently healthy people. The study adds that as many as 7,000 asymptomatic children in the US die from SCD each year, almost half of whom never show earlier symptoms.

In their findings, the researchers discussed that the majority of the ion-channel diseases are hereditary with an autosomal-dominant transmission, meaning that half of the children of individuals affected by SCD will be impacted as well.

In the event that sequence variations are identified, family members of the deceased should then undergo further medical tests. The researchers hope that these new findings will allow for individual risk analysis among impacted family members, who can then be provided with prophylactic treatment, such as an implantable cardioverter defibrillator.

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