SCN5A Variant Y774C

Summary of observed carriers, functional annotations, and structural context for SCN5A Y774C. Data combine curated literature, international cohorts, and gnomAD observations.

Estimated LQT3 penetrance

18%

1/12 effective observations

Estimated BrS1 penetrance

23%

2/12 effective observations

Total carriers

2

0 BrS1 · 0 LQT3 · 2 unaffected

Y774C is present in 2 alleles in gnomAD. This residue resides in a Mild_Hotspot region for Brugada syndrome and a Mild_Hotspot region for LQT3.

Variant features alone are equivalent to phenotyping 2 individuals for Brugada syndrome and 1 individuals for LQT3.

In silico predictors

Variant-level computational predictors.
PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density BrS (%) Penetrance Density LQT3 (%)
-8.74 0.994 -2.17 0.877 32 23

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
Literature, cohort, and gnomAD – 2 2 0 0 –
Variant features alone – 15 12 1 2 – –

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

Nearby variants

Neighbouring residues within 15 Ångström provide structural context. Variants listed in the right-most column have been observed clinically or in gnomAD.

Previously observed variants near Y774C.
Neighbour residue Distance (Å) Observed variants
774 0 p.Y774TfsX28, Y774D, Y774C, c.2320delT,
772 5 D772N,
767 14
770 12
775 6
771 10 L771V,
783 13 I783T,
769 12
773 4 P773S,
776 9 p.Y776del,
768 10
786 15
779 13 Q779X, Q779K,
777 8 F777L,
782 13 N782T,
778 9