SCN5A Variant Y389X

Summary of observed carriers, functional annotations, and structural context for SCN5A Y389X. Data combine curated literature, international cohorts, and gnomAD observations.

Estimated LQT3 penetrance

21%

1/11 effective observations

Estimated BrS1 penetrance

13%

1/11 effective observations

Total carriers

1

0 BrS1 · 1 LQT3 · 0 unaffected

Y389X has not been reported in gnomAD. This residue resides in a Mild_Hotspot region for Brugada syndrome and a Non_Hotspot region for LQT3.

Variant features alone are equivalent to phenotyping 1 individuals for Brugada syndrome and 0 individuals for LQT3.

In silico predictors

Variant-level computational predictors.
PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density BrS (%) Penetrance Density LQT3 (%)
NA NA NA None 12 2

PROVEAN scores below -2 suggest deleterious impact. REVEL scores above 0.5–0.75 are often interpreted as likely pathogenic. PolyPhen-2 scores above 0.85 are typically pathogenic. Penetrance density summarises neighbouring residue risk (Kroncke et al. 2019).

Reported carrier data

Observed carriers by publication or cohort.
Source Year Carriers Unaffected LQT3 BrS1 Other Other Disease
19716085 2009 1 1 0 0
Literature, cohort, and gnomAD – 1 0 1 0 –
Variant features alone – 15 14 0 1 – –

Totals may differ from individual publications due to duplicate patients removed during curation.

Functional data

Peak and late/persistent current values are relative to wild-type (100% indicates no change). V1/2 activation and inactivation denote the membrane potentials (mV) at which half-maximal current is achieved.

Published electrophysiology measurements.
PubMed ID Year Cell Type Peak Current (% WT) V1/2 Activation (mV) V1/2 Inactivation (mV) Late/Persistent Current (% WT)
19716085 2009