SCN5A Variant G1687A Detail

We estimate the penetrance of LQTS for SCN5A G1687A around 4% and the Brugada syndrome penetrance around 27%. SCN5A G1687A was found in a total of 0 carriers in 0 papers and/or in gnomAD: 0 had Brugada syndrome, 0 had LQTS. G1687A is not present in gnomAD. G1687A 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 G1687A around 4% (0/10) and the Brugada syndrome penetrance around 27% (2/10).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density BrS (%) Penetrance Density LQT3 (%)
NA NA NA 0.87 34 0
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.

G1687A has 57 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
333 13 c.998+1G>A, c.998+5G>A,
1702 12
1715 6
1687 0
1743 15 G1743E, G1743R,
1711 11 c.5131delG,
1707 12
1694 11
1704 13 L1704H,
1706 10 Q1706H,
1695 13 Q1695X,
376 10 R376H, R376C,
1716 6 p.L1716SfsX71,
1714 10 D1714G,
1688 4
1684 8 W1684R,
1692 7
1744 15 S1744I,
1721 13
1693 9
378 12
1699 12
373 14
1712 8 G1712C, G1712S,
379 7
1680 15 A1680T, A1680P,
1703 9
1719 7
325 14 L325R,
1420 13 G1420R, G1420D, G1420V, G1420P,
1690 10 D1690N, c.5068_5070delGA,
324 12
1399 14
1713 12
383 11
1748 15 p.G1748del, G1748D,
1683 11
382 13
1718 9 S1718R,
374 14 W374G,
1705 15
1689 6 D1689N,
1700 13
1717 10 L1717P,
1682 11
1752 13
381 15 c.1140+1G>A, c.1141-3C>A,
1686 4
375 9
1691 9
1710 15 S1710L,
380 12
1720 10 c.5157delC,
377 14
1679 13
1685 7
1419 13 K1419E,