Inherited Brugada and long QT-3 syndrome mutations of a single residue of the cardiac sodium channel confer distinct channel and clinical phenotypes.

Details

Serval ID
serval:BIB_DAD42DF91906
Type
Article: article from journal or magazin.
Collection
Publications
Institution
Title
Inherited Brugada and long QT-3 syndrome mutations of a single residue of the cardiac sodium channel confer distinct channel and clinical phenotypes.
Journal
Journal of Biological Chemistry
Author(s)
Rivolta I., Abriel H., Tateyama M., Liu H., Memmi M., Vardas P., Napolitano C., Priori S.G., Kass R.S.
ISSN
0021-9258
Publication state
Published
Issued date
08/2001
Peer-reviewed
Oui
Volume
276
Number
33
Pages
30623-30630
Language
english
Abstract
Defects of the SCN5A gene encoding the cardiac sodium channel alpha-subunit are associated with both the long QT-3 (LQT-3) subtype of long-QT syndrome and Brugada syndrome (BrS). One previously described SCN5A mutation (1795insD) in the C terminus results in a clinical phenotype combining QT prolongation and ST segment elevation, indicating a close interrelationship between the two disorders. Here we provide additional evidence that these two disorders are closely related. We report the analysis of two novel mutations on the same codon, Y1795C (LQT-3) and Y1795H (BrS), expressed in HEK 293 cells and characterized using whole-cell patch clamp procedures. We find marked and opposing effects on channel gating consistent with activity associated with the cellular basis of each clinical disorder. Y1795H speeds and Y1795C slows the onset of inactivation. The Y1795H, but not the Y1795C, mutation causes a marked negative shift in the voltage dependence of inactivation, and neither mutation affects the kinetics of the recovery from inactivation. Interestingly, both mutations increase the expression of sustained Na+ channel activity compared with wild type (WT) channels, although this effect is most pronounced for the Y1795C mutation, and both mutations promote entrance into an intermediate or a slowly developing inactivated state. These data confirm the key role of the C-terminal tail of the cardiac Na+ channel in the control of channel gating, illustrate how subtle changes in channel biophysics can have significant and distinct effects in human disease, and, additionally, provide further evidence of the close interrelationship between BrS and LQT-3 at the molecular level.
Keywords
Heart Block/genetics, Humans, Long QT Syndrome/genetics, Mutation, Phenotype, Sodium Channels/genetics, Sodium Channels/physiology
Pubmed
Web of science
Open Access
Yes
Create date
24/01/2008 10:56
Last modification date
20/08/2019 15:59
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