Clinical Information

Sudden cardiac death (SCD) is estimated to occur at an incidence of between 50 to 100 per 100,000 individuals in North America and Europe each year, claiming between 250,000 and 450,000 lives in the United States annually. In younger individuals (15-35 years of age), the incidence of SCD is between 1 to 2 per 100,000 young individuals. The reported incidence of SCD is likely an underestimate since more overt causes of death, such as car accidents and drownings, may result from arrhythmogenic events. In cases of sudden unexplained death where autopsy does not detect a structural basis for sudden death, a hereditary arrhythmia may be suspected.

Cardiac arrhythmias are a group of conditions characterized by abnormal heart rhythms. Arrhythmias can be caused by either genetic (inherited) factors or nongenetic (acquired) causes, such as medications and infection. Hereditary forms of cardiac arrhythmias for which this panel assesses include, but are not limited to, long QT syndrome, short QT syndrome, catecholaminergic polymorphic ventricular tachycardia, Brugada syndrome, arrhythmogenic right ventricular cardiomyopathy, and familial atrial fibrillation.(1) This gene panel also assesses genes associated with rarer, syndromic conditions in which cardiac arrhythmia is a major feature, such as Andersen-Tawil syndrome, Carvajal syndrome, Jervell and Lange-Nielsen syndrome, Naxos disease, Timothy syndrome, and Emery-Dreifuss muscular dystrophy.(1-3)

Inherited cardiac arrhythmias can follow autosomal dominant, autosomal recessive, X-linked, and digenic patterns of inheritance. Genes associated with mitochondrial inheritance of cardiac arrhythmias are not assessed on this panel.

Postmortem diagnosis of a hereditary arrhythmia may assist in confirmation of the cause and manner of death as well as risk assessment in living family members.