In:
Circulation: Cardiovascular Genetics, Ovid Technologies (Wolters Kluwer Health), Vol. 5, No. 4 ( 2012-08), p. 450-459
Abstract:
Atrial fibrillation (AF) is the most common cardiac arrhythmia. The cardiac sodium channel, Na V 1.5, plays a pivotal role in setting the conduction velocity and the initial depolarization of the cardiac myocytes. We hypothesized that early-onset lone AF was associated with genetic variation in SCN5A . Methods and Results— The coding sequence of SCN5A was sequenced in 192 patients with early-onset lone AF. Eight nonsynonymous mutations (T220I, R340Q, T1304M, F1596I, R1626H, D1819N, R1897W, and V1951M) and 2 rare variants (S216L in 2 patients and F2004L) were identified. Of 11 genopositive probands, 6 (3.2% of the total population) had a variant previously associated with long QT syndrome type 3 (LQTS3). The prevalence of LQTS3-associated variants in the patients with lone AF was much higher than expected, compared with the prevalence in recent exome data (minor allele frequency, 1.6% versus 0.3%; P =0.003), mainly representing the general population. The functional effects of the mutations were analyzed by whole cell patch clamp in HEK293 cells; for 5 of the mutations previously associated with LQTS3, patch-clamp experiments showed an increased sustained sodium current, suggesting a mechanistic overlap between LQTS3 and early-onset lone AF. In 9 of 10 identified mutations and rare variants, we observed compromised biophysical properties affecting the transient peak current. Conclusions— In a cohort of patients with early-onset lone AF, we identified a high prevalence of SCN5A mutations previously associated with LQTS3. Functional investigations of the mutations revealed both compromised transient peak current and increased sustained current.
Type of Medium:
Online Resource
ISSN:
1942-325X
,
1942-3268
DOI:
10.1161/CIRCGENETICS.111.962597
Language:
English
Publisher:
Ovid Technologies (Wolters Kluwer Health)
Publication Date:
2012
detail.hit.zdb_id:
2927603-2
detail.hit.zdb_id:
2457085-0
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