SCN5A Variant S910L Detail

We estimate the penetrance of LQTS for SCN5A S910L around 5% and the Brugada syndrome penetrance around 56%. SCN5A S910L was found in a total of 5 carriers in 6 papers and/or in gnomAD: 4 had Brugada syndrome, 0 had LQTS. S910L is present in 1 alleles in gnomAD. S910L has been functionally characterized in 6 papers. This residue is located in a Mild_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 (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 S910L around 5% (0/15) and the Brugada syndrome penetrance around 56% (8/15).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density BrS (%) Penetrance Density LQT3 (%)
-2.62 0.982 -2.34 0.808 58 14
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
24768612 2014 3 0 3 0
11901046 2002 1 0 1 0
28104484 2017 1 0 0 1 SSS
20129283 2010 1 0 1 0
29325976 2018 2 0 2 0
29574140 2018 1 0 1 0
LITERATURE, COHORT, AND GNOMAD: - 5 1 0 4 -
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
24768612 2014 HEK 0
29325976 2018
29574140 2018
11901046 2002
28104484 2017

S910L has 50 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
880 14
856 14 V856L,
890 15 I890T,
901 15 E901K, S901L,
919 12
870 13
862 9
867 10 E867Q, E867K, E867X,
859 13
360 15
863 9
904 12 W904X,
864 6
216 13 S216L, S216X,
871 12
909 4
876 14
857 11 G857D,
868 9 L868X, c.2602delC,
902 12
882 14
881 10
860 9 p.L860fsx89,
911 4 G911E,
900 15
858 14 M858L,
217 15
918 12
917 12 L917R, L917V,
865 8
913 6
916 11
912 7 Q912R,
906 5
866 11 S866L, S866P,
351 15 G351C, G351S, G351D, G351V,
910 0 S910L,
350 13 H350Q,
903 10 p.M903CfsX29,
877 14
869 13 R869S,
905 9
352 12 Y352C,
915 7 C915R,
215 14 p.L215CfsX10,
908 7
914 7
861 6 p.F861WfsX90, c.2582_2583delTT,
220 14 T220I,
907 7