SCN5A Variant T1779K Detail

We estimate the penetrance of LQTS for SCN5A T1779K around 32% and the Brugada syndrome penetrance around 18%. SCN5A T1779K was found in a total of 0 carriers in 0 papers and/or in gnomAD: 0 had Brugada syndrome, 0 had LQTS. T1779K is not present in gnomAD. T1779K 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 T1779K around 32% (1/10) and the Brugada syndrome penetrance around 18% (1/10).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density BrS (%) Penetrance Density LQT3 (%)
NA NA NA 0.886 18 40
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.

T1779K has 64 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,
1785 10
1643 12 I1643L,
1778 4
1773 11
249 11 K249X,
1653 14
1771 12 I1771T,
1652 12 M1652T, M1652R,
1777 6 V1777M, V1777L,
418 10 E418K,
250 14
409 14 L409P, L409V,
1650 12 L1650F,
1492 13
1641 12
417 12
1477 15 K1477N,
246 14
1779 0 T1779M,
412 13 V412D,
1493 10 p.K1493del, K1493X, K1493R,
245 14 Q245K,
1776 5
1787 10 S1787N,
1786 12 L1786R, L1786Q, c.5356_5357delCT,
1648 11
1769 15
415 11 A415T,
1649 9 A1649V,
1774 9 N1774D, c.5321_5324dupACTT,
1644 13 R1644H, R1644C, R1644L,
1640 15
1496 13
1474 14
1781 7 E1781D, E1781G,
1789 13
1772 11 L1772V,
1645 8 T1645M,
1784 11 E1784K, E1784X,
410 9 A410V,
1780 4 E1780G,
1788 13 c.5361_5364delTGAG,
1770 15 I1770V,
1651 15
416 15 Y416C,
1500 15 p.K1500del,
413 11 A413E, A413T,
408 14
253 14
407 12
1783 7
1775 6 F1775V, p.F1775LfsX15,
1642 10 G1642E,
421 14
1497 15
1490 14
1790 14 p.D1790del, D1790G, D1790N,
252 14
411 10 V411M,
1647 13
1646 9
1489 12 E1489D,
1782 5