Referenced in: none

Automatically associated channels: Kv12.1 , Nav1.8

Title: SCN10A/Nav1.8 modulation of peak and late sodium currents in patients with early onset atrial fibrillation.

Authors: Eleonora Savio-Galimberti, Peter Weeke, Raafia Muhammad, Marcia Blair, Sami Ansari, Laura Short, Thomas C Atack, Kaylen Kor, Carlos G Vanoye, Morten Salling Olesen, LuCamp, Tao Yang, Alfred L George, Dan M Roden, Dawood Darbar

Journal, date & volume: Cardiovasc. Res., 2014 Nov 1 , 104, 355-63

PubMed link: http://www.ncbi.nlm.nih.gov/pubmed/25053638

Abstract
To test the hypothesis that vulnerability to atrial fibrillation (AF) is associated with rare coding sequence variation in the SCN10A gene, which encodes the voltage-gated sodium channel isoform NaV1.8 found primarily in peripheral nerves and to identify potentially disease-related mechanisms in high-priority rare variants using in-vitro electrophysiology.We re-sequenced SCN10A in 274 patients with early onset AF from the Vanderbilt AF Registry to identify rare coding variants. Engineered variants were transiently expressed in ND7/23 cells and whole-cell voltage clamp experiments were conducted to elucidate their functional properties. Resequencing SCN10A identified 18 heterozygous rare coding variants (minor allele frequency ≤1%) in 18 (6.6%) AF probands. Four probands were carriers of two rare variants each and 14 were carriers of one coding variant. Based on evidence of co-segregation, initial assessment of functional importance, and presence in ≥1 AF proband, three variants (417delK, A1886V, and the compound variant Y158D-R814H) were selected for functional studies. The 417delK variant displayed near absent current while A1886V and Y158D-R814H exhibited enhanced peak and late (INa-L) sodium currents; both Y158D and R818H individually contributed to this phenotype.Rare SCN10A variants encoding Nav1.8 were identified in 6.6% of patients with early onset AF. In-vitro electrophysiological studies demonstrated profoundly altered function in 3/3 high-priority variants. Collectively, these data strongly support the hypothesis that rare SCN10A variants may contribute to AF susceptibility.