SCN5A Variant E677A Detail

We estimate the penetrance of LQTS for SCN5A E677A around 6% and the Brugada syndrome penetrance around 14%. SCN5A E677A was found in a total of 0 carriers in 0 papers and/or in gnomAD: 0 had Brugada syndrome, 0 had LQTS. E677A is not present in gnomAD. E677A has been functionally characterized in 0 papers. This residue is located in a Mild_Hotspot region for Brugada syndrome and a Non_Hotspot region for LQTS. In silico predictions, functional data (if available), and location in structure are equivalent to phenotyping 10 individuals for Brugada syndrome (1 diagnosed with Brugada syndrome) and 5 individuals for LQTS (0 with LQTS). These data combined with observations of carriers lead us to estimate the LQTS penetrance for SCN5A E677A around 6% (0/10) and the Brugada syndrome penetrance around 14% (1/10).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density BrS (%) Penetrance Density LQT3 (%)
NA NA NA 0.787 12 4
PROVEAN scores less than -2 are considered deleterious. REVEL scores higher than 0.5 or 0.75 are considered likely pathogenic (higher sensitivity with the former cutoff, higher specificity with the latter cutoff). A PolyPhen-2 score of 0.85 or greater is considered likely pathogenic. BLAST-PSSM reflects the evolutionary conservation of residue substitutions, more negative numbers indicate fewer observations of the specific substitution than is expected. Penetrance Density is our previously published method to calculate the average BrS/LQTS probability density in a shell of residues surrounding a residue of interest (Kroncke et al. 2019).

Reported Carrier Data

PubMed ID Year Carriers Unaffected LQT3 BrS1 Other Other Disease
LITERATURE, COHORT, AND GNOMAD: - 0 0 0 0 -
VARIANT FEATURES ALONE: - 15 14 0 1 - -
Summary totals might not agree with the literature table because of duplicate patients, which were excluded from the total counts. We do not distinguish here between multiple missense codons. Missense variants are combined across degenerate codon substitutions since codon-level data were not consistently available for curation.

E677A has 31 previously observed neighbors within 15 angstroms

A residue within a folded protein on average has nearest neighbors that fall roughly into two shells: a "nearest" neighbor around 5-6 angstroms and a second shell around 11 angstroms. All variants shown in the rightmost column have been observed in at least one individual in the literature or gnomAD.

Neighbor Distance (Angstroms) Variants Observed in Individuals
662 15 A662S, c.1983_1993dupGGCCCTCAGCG,
663 14
664 14 S664G,
665 13 A665T, A665S,
666 13
667 12
668 11 V668I,
669 11
670 10
671 9 S671C,
672 8 A672T, A672S,
673 8 L673V, L673P,
674 7
675 5 c.2024_2025delAG,
676 4
677 0 E677V,
678 4
679 5
680 7 R680C, R680H,
681 8 H681P,
682 8
683 9 C683R, C683S, C683G,
684 10
685 11
686 11 C686F,
687 12
688 13
689 13 R689C, R689H,
690 14
691 14 A691T, A691S,
692 15 Q692K,