exon 8 mutations has been described, to date. In contrast to multiorgan disease caused by G406R either in exon 8A or 8, the G402S carrier manifested only an isolated cardiac phenotype with LQT and cardiac arrest. This isolated phenotype was suggested to be a cause of somatic mosaicism. We describe a teenage patient resuscitated from ventricular fibrillation and treated with ICD. She has no other organ manifestations, no syndactyly, her QTc is <480ms, and she has normal neurodevelopment. There is no family history of arrhythmias or sudden deaths. Targeted oligonucleotideselective sequencing of channelopathy genes revealed a de novo G402S in the exon 8 of CACNA1C. Direct sequencing of blood and oral mucosa derived DNA revealed an identical mutation peak suggesting the mutation is not expressed as mosaicism. The phenotype of our patient and the previously described patient show an isolated arrhythmia disease with no clinical manifestations of TS. Based on current evidence, we suggest the G402S mutation in CACNA1C should not be considered as causative for TS.