SCN5A Variant S1776T Detail

We estimate the penetrance of LQTS for SCN5A S1776T around 36% and the Brugada syndrome penetrance around 17%. SCN5A S1776T was found in a total of 0 carriers in 0 papers and/or in gnomAD: 0 had Brugada syndrome, 0 had LQTS. S1776T is not present in gnomAD. S1776T 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 S1776T around 36% (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 0.787 17 47
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.

S1776T has 65 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 7 M414V,
939 12 L939F,
1785 13
1778 6
1773 6
249 14 K249X,
1653 12
1771 9 I1771T,
1652 10 M1652R, M1652T,
1777 4 V1777M, V1777L,
1487 15 M1487K, M1487L,
418 12 E418K,
409 11 L409P, L409V,
1650 12 L1650F,
1492 12
417 10
1477 11 K1477N,
1471 13
1779 5 T1779M,
412 12 V412D,
935 15 L935P,
1493 11 K1493R, K1493X, p.K1493del,
1470 11
1466 15 c.4396_4397insG,
1478 13 K1478E,
1776 0
1787 13 S1787N,
1648 12
1769 10
415 11 A415T,
1649 9 A1649V,
1768 13 I1768V,
940 14 S940N,
1774 6 c.5321_5324dupACTT, N1774D,
1473 12 F1473C, F1473S,
1496 13
1474 10
1781 8 E1781G, E1781D,
1772 7 L1772V,
1645 11 T1645M,
1488 14 T1488R,
1784 14 E1784X, E1784K,
410 8 A410V,
1780 6 E1780G,
1788 15 c.5361_5364delTGAG,
1770 11 I1770V,
1651 15
416 14 Y416C,
413 9 A413T, A413E,
408 14
407 11
1783 11
936 13
1467 15
1775 5 F1775V, p.F1775LfsX15,
1642 14 G1642E,
421 14
1490 14
1475 15 Q1475L, p.Q1475NfsX6,
406 13 N406K, N406S,
411 10 V411M,
1647 14
1646 11
1489 10 E1489D,
1782 10