SCN5A Variant A1778V Detail

We estimate the penetrance of LQTS for SCN5A A1778V around 35% and the Brugada syndrome penetrance around 17%. SCN5A A1778V was found in a total of 0 carriers in 0 papers and/or in gnomAD: 0 had Brugada syndrome, 0 had LQTS. A1778V is not present in gnomAD. A1778V has been functionally characterized in 0 papers. This residue is located in a Mild_Hotspot region for Brugada syndrome and a 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 (1 with LQTS). These data combined with observations of carriers lead us to estimate the LQTS penetrance for SCN5A A1778V around 35% (1/10) and the Brugada syndrome penetrance around 17% (1/10).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density BrS (%) Penetrance Density LQT3 (%)
NA NA NA 0.929 16 45
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 1 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.

A1778V has 58 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
414 10 M414V,
1785 9
1643 12 I1643L,
1778 0
1773 10
249 14 K249X,
1653 11
1771 11 I1771T,
1652 8 M1652R, M1652T,
1777 4 V1777M, V1777L,
418 14 E418K,
1650 10 L1650F,
1492 12
1641 12
417 15
1477 13 K1477N,
1779 4 T1779M,
1493 9 K1493R, K1493X, p.K1493del,
1776 6
1787 8 S1787N,
1654 15
1786 10 L1786Q, c.5356_5357delCT, L1786R,
1648 7
1769 14
415 14 A415T,
1495 15 Y1495S,
1649 7 A1649V,
1774 7 c.5321_5324dupACTT, N1774D,
1644 12 R1644L, R1644H, R1644C,
1640 15
1496 10
1474 14
1781 5 E1781G, E1781D,
1789 11
1772 11 L1772V,
1645 7 T1645M,
1784 12 E1784X, E1784K,
410 11 A410V,
1780 6 E1780G,
1788 10 c.5361_5364delTGAG,
1770 13 I1770V,
1651 12
1500 12 p.K1500del,
413 13 A413T, A413E,
1791 13
1792 14 D1792Y, D1792N, D1792V,
407 13
1783 9
1775 6 F1775V, p.F1775LfsX15,
1642 10 G1642E,
1497 12
1490 14
1790 12 D1790N, D1790G, p.D1790del,
411 12 V411M,
1647 11
1646 8
1489 12 E1489D,
1782 6