The exact mechanism of the electrocardiographic changes and the development of ventricular fibrillation and sudden death remain undetermined. Electrically active cardiac cells possess sodium channels; an outward sodium current is counterbalanced by an inward sodium current. It appears that in this syndrome the inward current is attenuated and some of the electrocardiographic features can be partly explained based on changes in sodium currents. The syndrome is a disorder of sodium cardiac channel func¬tion that triggers the electrocardiographic changes and malignant arrhythmias, particularly ventricular fibrillation. Mutations in a gene responsible for the sodium chan¬nel have been identified in some families with this syn¬drome. More than three different mutations on the cardiac sodium channel gene SCN5A on chromosome 3 have been described. Mutations on other genes are being sought. Further research is required in this area and its results are of extreme importance to prevent deaths in young individuals.