Analyses of a novel SCN5A mutation (C1850S): conduction vs. repolarization disorder hypotheses in the Brugada syndrome.
Détails
Etat: Public
Version: Final published version
Licence: Non spécifiée
It was possible to publish this article open access thanks to a Swiss National Licence with the publisher.
ID Serval
serval:BIB_5C6A69C155CE
Type
Article: article d'un périodique ou d'un magazine.
Sous-type
Etude de cas (case report): rapporte une observation et la commente brièvement.
Collection
Publications
Institution
Titre
Analyses of a novel SCN5A mutation (C1850S): conduction vs. repolarization disorder hypotheses in the Brugada syndrome.
Périodique
Cardiovascular Research
ISSN
0008-6363
Statut éditorial
Publié
Date de publication
2008
Peer-reviewed
Oui
Volume
78
Numéro
3
Pages
494-504
Langue
anglais
Notes
Publication types: Case Reports ; Journal Article ; Research Support, Non-U.S. Gov't
Résumé
AIMS: Brugada syndrome (BrS) is characterized by arrhythmias leading to sudden cardiac death. BrS is caused, in part, by mutations in the SCN5A gene, which encodes the sodium channel alpha-subunit Na(v)1.5. Here, we aimed to characterize the biophysical properties and consequences of a novel BrS SCN5A mutation. METHODS AND RESULTS: SCN5A was screened for mutations in a male patient with type-1 BrS pattern ECG. Wild-type (WT) and mutant Na(v)1.5 channels were expressed in HEK293 cells. Sodium currents (I(Na)) were analysed using the whole-cell patch-clamp technique at 37 degrees C. The electrophysiological effects of the mutation were simulated using the Luo-Rudy model, into which the transient outward current (I(to)) was incorporated. A new mutation (C1850S) was identified in the Na(v)1.5 C-terminal domain. In HEK293 cells, mutant I(Na) density was decreased by 62% at -20 mV. Inactivation of mutant I(Na) was accelerated in a voltage-dependent manner and the steady-state inactivation curve was shifted by 11.6 mV towards negative potentials. No change was observed regarding activation characteristics. Altogether, these biophysical alterations decreased the availability of I(Na). In the simulations, the I(to) density necessary to precipitate repolarization differed minimally between the two genotypes. In contrast, the mutation greatly affected conduction across a structural heterogeneity and precipitated conduction block. CONCLUSION: Our data confirm that mutations of the C-terminal domain of Na(v)1.5 alter the inactivation of the channel and support the notion that conduction alterations may play a significant role in the pathogenesis of BrS.
Mots-clé
Action Potentials, Brugada Syndrome, Cell Line, Computer Simulation, Defibrillators, Implantable, Electrocardiography, Genetic Predisposition to Disease, Heart Conduction System, Heart Rate, Humans, Kinetics, Male, Middle Aged, Models, Cardiovascular, Muscle Proteins, Mutation, Patch-Clamp Techniques, Phenotype, Protein Structure, Tertiary, Sodium, Sodium Channels, Transfection
Pubmed
Web of science
Open Access
Oui
Création de la notice
29/01/2009 23:13
Dernière modification de la notice
14/02/2022 8:55