A patient (Figure 1A, II-3) presented with severe cardiac conduction abnormalities and ventricular arrhythmias early after birth and was genetically characterized as carrying bi-allelic mutations in the SCN5A gene.31 These were a c.468G>A nucleotide change in exon 4 of SCN5A (NM_198056.2) inherited from the father, leading to the stop codon mutation p.W156X (NP_932173.1), and a c.673C>T nucleotide change in exon 6B of SCN5A inherited from the mother. Here, SCN5A is linked to Ventricular arrhythmia.