SCN5A Variant S1718I Detail

We estimate the penetrance of LQTS for SCN5A S1718I around 3% and the Brugada syndrome penetrance around 24%. SCN5A S1718I was found in a total of 0 carriers in 0 papers and/or in gnomAD: 0 had Brugada syndrome, 0 had LQTS. S1718I is not present in gnomAD. S1718I 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 (2 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 S1718I around 3% (0/10) and the Brugada syndrome penetrance around 24% (2/10).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density BrS (%) Penetrance Density LQT3 (%)
NA NA NA 0.635 30 1
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 13 0 2 - -
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.

S1718I has 59 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
1746 13 A1746T, A1746V,
1724 13
1741 14 D1741Y, D1741N, D1741E,
1715 5
1687 9
1745 10
1397 13 c.4189delT, c.4190delA,
1743 11 G1743E, G1743R,
1711 14 c.5131delG,
1723 9 T1723N,
1707 14
1725 13 P1725L,
1398 11 V1398M,
1694 13
1411 12
1407 13
1410 11
1706 15 Q1706H,
1747 13 V1747M,
1716 7 p.L1716SfsX71,
1714 6 D1714G,
1688 10
1684 12 W1684R,
1423 12 D1423H,
1692 15
1744 10 S1744I,
1721 5
1753 14 T1753A,
1742 14
1693 15
1712 10 G1712C, G1712S,
1703 14
1719 4
1408 15 G1408R,
1420 11 G1420P, G1420V, G1420R, G1420D,
1401 12
1399 6
1713 11
1424 13 I1424V,
1748 10 G1748D, p.G1748del,
1683 11
1400 9 V1400I,
1718 0 S1718R,
1689 14 D1689N,
1717 5 L1717P,
1751 13
1682 11
1750 15 L1750F,
1752 10
1722 9 N1722D,
1686 7
1749 11 I1749N,
375 14
1720 6 c.5157delC,
1679 12
1685 7
1419 13 K1419E,
1414 11 Q1414H,
1413 14