SCN5A Variant C1703G Detail

We estimate the penetrance of LQTS for SCN5A C1703G around 4% and the Brugada syndrome penetrance around 22%. SCN5A C1703G was found in a total of 0 carriers in 0 papers and/or in gnomAD: 0 had Brugada syndrome, 0 had LQTS. C1703G is not present in gnomAD. C1703G 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 C1703G around 4% (0/10) and the Brugada syndrome penetrance around 22% (2/10).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density BrS (%) Penetrance Density LQT3 (%)
NA NA NA 0.96 25 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.

C1703G has 81 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 14 c.998+5G>A, c.998+1G>A,
1702 5
387 12
1715 10
1687 9
388 15 I388S,
1698 8 A1698T,
1756 14 I1756V,
1673 13
1675 11
1711 9 c.5131delG,
332 15 A332T,
1707 6
1694 6
1704 5 L1704H,
1226 15
1706 5 Q1706H,
1695 11 Q1695X,
376 14 R376H, R376C,
1716 7 p.L1716SfsX71,
1714 13 D1714G,
1688 9
1684 14 W1684R,
1669 14
1671 12
1668 9 M1668T,
1676 11 M1676T, M1676I,
1692 6
386 14 G386E, G386R,
1672 9 S1672Y,
1693 7
378 8
1699 6
331 14
1665 14
1712 9 G1712C, G1712S,
379 9
1680 13 A1680T, A1680P,
1703 0
1759 14 S1759C,
1719 12
1709 11 p.T1709del, T1709M, T1709R,
1701 7 M1701I,
1690 12 c.5068_5070delGA, D1690N,
1678 14 N1678S,
1755 11
1697 11
393 13
1674 14 F1674V,
1713 10
390 11
394 14
383 13
1748 14 G1748D, p.G1748del,
1708 9 T1708I,
382 11
1718 14 S1718R,
1696 10
374 11 W374G,
1705 7
1689 10 D1689N,
1700 5
1717 12 L1717P,
1751 11
1677 15
1682 13
1752 10
1670 14
381 14 c.1141-3C>A, c.1140+1G>A,
1686 12
375 10
1691 9
1710 12 S1710L,
380 14
1720 12 c.5157delC,
377 14
1679 11
1685 14
1419 15 K1419E,
1667 13 V1667I,
1664 14