[Genetic aspects of the etiology of arrhythmia]

Cardiac arrhythmias are common causes of morbidity and mortality in clinical medicine. Much has been learned about cellular mechanisms of arrhythmogenesis in the past but genetic components have only recently been recognized for some heritable forms of arrhythmias. The long QT syndrome and the Brugada syndrome are both caused by molecular defects in ion channel proteins. Cardiac arrhythmias can also be associated with structural heart diseases. For example, sinus node dysfunction or AV-block can precede some forms of inherited dilated cardiomyopathy. A distinct genetic form of hypertrophic cardiomyopathy is associated with the Wolff-Parkinson-White syndrome and maps to chromosome 7q35. Arrhythmogenic right ventricular cardiomyopathy has a strong genetic basis and often manifests with ventricular tachycardia. Atrial fibrillation can also occur as familial disease and may be allelic with dilated cardiomyopathy as both diseases can be closely linked to chromosome 10q2.