Ten years of genes in inherited arrhythmia syndromes: an example of what we have learned from patients, electrocardiograms, and computers.

In the last 10 years the molecular substrate of a diversity of primary electrical diseases has been unraveled. Disease-causing mutations in ion-channel genes have been identified and have challenged clinical and basic electrophysiologists to mechanistically link the observed genetic aberrancies to the phenotype. Indeed, in collaborative efforts of clinical cardiologists, clinical and molecular geneticists, basic electrophysiologists and computer modellers, the pathophysiology of many clinical electrocardiographic findings have been elucidated in detail. The family described concerns an 8-generation SCN5a-linked family with a high incidence of nocturnal sudden death. The phenotype is characterised by bradycardia-dependent QT-prolongation, right precordial ST-elevation, conduction disease at all cardiac compartments, and sinus node disfunction. Heterologous expression of the mutant sodium channels demonstrated altered channel characteristics which, introduced in elegant computer modeling studies, nicely explained the complex phenotype. As such these studies serve as a good example of what can be reached in a multidisciplinary approach with clinical and basic scientists.