Correlation between <i>SCN5A</i> mutations, the patients' phenotypes, and electrophysiological properties of hNa_v1.5 mutant channels associated with SSS and other <i>SCN5A</i> channelopathies.

<p>Loss-of-function features in heterologously expressed hNa_v1.5 mutant channels, compared to wild-type hNa_v1.5, are highlighted (bold). F - number of affected families, P - number of patients carrying the mutation(s), I - inheritability for SSS, n.s. - not shown.</p>a)<p>Observed only in <i>Xenopus</i> oocytes.</p>b)<p>Observed only in HEK293 cells.</p>c)<p>Reduced voltage dependency of channel inactivation, resulting in faster current decay at less depolarized potentials and slower decay at more depolarized potentials (<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0010985#pone-0010985-g002" target="_blank">Fig. 2F</a>).</p>d)<p>R1623X alone caused BrS plus SSS in another unrelated patient <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0010985#pone.0010985-Makiyama1" target="_blank">[31]</a>.</p>e)<p>Atrial standstill in this patient was related to a Cx40 polymorphism <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0010985#pone.0010985-Makita1" target="_blank">[34]</a>.</p>f)<p>In other studies, D1275N was related to atrial flutter, cardiac conduction defects, and bradycardia <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0010985#pone.0010985-LaitinenForsblom1" target="_blank">[27]</a>, and in combination with a rare Cx40 polymorphism in another family, with atrial standstill <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0010985#pone.0010985-Groenewegen1" target="_blank">[17]</a>.