SCN5A Variant G1935S Detail

We estimate the penetrance of LQTS for SCN5A G1935S around 16% and the Brugada syndrome penetrance around 11%. SCN5A G1935S was found in a total of 10 carriers in 6 papers and/or in gnomAD: 1 had Brugada syndrome, 2 had LQTS. G1935S is present in 7 alleles in gnomAD. G1935S has been functionally characterized in 6 papers. This residue is located in a Non_Hotspot region for Brugada syndrome and a Mild_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 (0 with LQTS). These data combined with observations of carriers lead us to estimate the LQTS penetrance for SCN5A G1935S around 16% (2/20) and the Brugada syndrome penetrance around 11% (2/20).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density BrS (%) Penetrance Density LQT3 (%)
-0.78 0.001 1.23 0.592 6 11
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
18508782 2008 1 0 0 1 SD
20541041 2010 1 1 0 0
27816319 2017 1 1 0 0
26746457 2016 1 1 0 0
20129283 2010 1 0 1 0
29325976 2018 1 0 1 0
LITERATURE, COHORT, AND GNOMAD: - 10 7 2 1 -
VARIANT FEATURES ALONE: - 15 14 0 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.

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)
18508782 2008
20541041 2010
27816319 2017
26746457 2016
20129283 2010
29325976 2018

G1935S has 31 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
1920 15 S1920C,
1921 14
1922 14 K1922N, K1922R,
1923 13 H1923Y, H1923D,
1924 13 A1924T,
1925 12 S1925F, p.S1925CfsX20,
1926 11
1927 11 L1927P,
1928 10 F1928V,
1929 9 R1929H, R1929C,
1930 8 Q1930H,
1931 8
1932 7 A1932V,
1933 5 G1933D, G1933V, G1933A,
1934 4
1935 0 G1935S,
1936 4
1937 5 S1937A,
1938 7 E1938X, E1938K,
1939 8 p.E1939_E1943del,
1940 8
1941 9
1942 10 P1942S, P1942H,
1943 11
1944 11 R1944X, R1944Q,
1945 12
1946 13
1947 13
1948 14 I1948V,
1949 14 A1949S, A1949T,
1950 15 Y1950C,