Mutational screening of SCN5A linked disorders in Polish patients and their family members

Mutations in SCN5A lead to a broad spectrum of phenotypes, including the Long QT syndrome, Brugada syndrome, Idiopathic ventricular fibrillation (IVF), Sudden infant death syndrome (SIDS) (probably regarded as a form of LQT3), Sudden unexplained nocturnal death syndrome (SUNDS) and isolated progressive cardiac conduction defect (PCCD) (Lev-Lenegre disease). Brugada Syndrome (BS) is a form of idiopathic ventricular fibrillation characterized by the right bundle-branch block pattern and ST elevation (STE) in the right precordial leads of the ECG. Mutations of the cardiac sodium channel SCN5A cause the disorder, and an implantable cardioverter-defibrillator is often recommended for affected individuals. In this study sequences of the coding region of the SCN5A gene were analysed in patients with the LQT3, Brugada Syndrome and other arrythmogenic disorders. Different mSSCP patterns are described with no disease-related SSCP conformers in any sample. Direct sequencing of the SCN5A gene confirmed the absence of mutations. This suggests that the analysed region of the SCN5A gene is not commonly involved in the pathogenesis of the Brugada Syndrome and associated disorders.