SCN5A Variant G1642E Detail

We estimate the penetrance of LQTS for SCN5A G1642E around 9% and the Brugada syndrome penetrance around 49%. SCN5A G1642E was found in a total of 1 carriers in 1 papers and/or in gnomAD: 1 had Brugada syndrome, 0 had LQTS. G1642E is not present in gnomAD. G1642E has been functionally characterized in 2 papers. This residue is located in a 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 (4 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 G1642E around 9% (0/11) and the Brugada syndrome penetrance around 49% (5/11).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density BrS (%) Penetrance Density LQT3 (%)
-7.37 1 -3.45 0.989 58 9
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
20129283 2010 1 0 1 0
LITERATURE, COHORT, AND GNOMAD: - 1 0 0 1 -
VARIANT FEATURES ALONE: - 15 11 0 4 - -
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.

Functional Data

Peak and late/persistent current are relative to wildtype (100% being no different from wildtype). V0.5 act/inact are the voltages at which half of the maximal current is reached during an activation and inactivation protocol, each is in units of mV and relative to wildtype.
PubMed ID Year Cell Type Peak Current (%WT) V1/2 Act. (mV) V1/2 Inact. (mV) Late/Persistent Current (%WT)
20129283 2010
32533946 2020 HEK 15 3.8 6.6

G1642E has 53 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 12 M414V,
1643 4 I1643L,
404 14 L404Q, L404V,
1778 10
249 9 K249X,
247 15 V247L,
254 12
1652 15 M1652R, M1652T,
1634 12 L1634P,
1777 14 V1777L, V1777M,
250 11
1650 12 L1650F,
1641 6
1639 8 G1639A,
246 14
1779 10 T1779M,
245 14 Q245K,
1776 14
1787 12 S1787N,
1648 11
415 15 A415T,
1649 11 A1649V,
1774 15 c.5321_5324dupACTT, N1774D,
1644 7 R1644L, R1644H, R1644C,
1640 5
256 10
248 13
1781 13 E1781G, E1781D,
1789 11
255 11
1645 5 T1645M,
251 9
410 13 A410V,
1780 14 E1780G,
1788 14 c.5361_5364delTGAG,
1638 11 R1638Q, R1638X,
1651 13
1633 14
1637 9
408 14
253 9
1636 14
407 11
1783 13
1775 10 p.F1775LfsX15, F1775V,
1642 0 G1642E,
1790 13 D1790N, p.D1790del, D1790G,
252 6
411 11 V411M,
1647 8
257 14
1646 6
1782 10