Although the percentage of pathogenic SCN5A mutations in ARVC is very low, PKP2 knockdown and overexpression of Dsg2 mutations both result in a decrease in INa (38, 39), and such a decrease in INa is proposed to be a critical factor in arrhythmogenesis in ARVC (40). The gene discussed is PKP2; the disease is arrhythmogenic right ventricular cardiomyopathy.