SCN5A Variant G1129C Detail

We estimate the penetrance of LQTS for SCN5A G1129C around 2% and the Brugada syndrome penetrance around 13%. SCN5A G1129C was found in a total of 0 carriers in 0 papers and/or in gnomAD: 0 had Brugada syndrome, 0 had LQTS. G1129C is not present in gnomAD. G1129C has been functionally characterized in 0 papers. This residue is located in a Mild_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 (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 G1129C around 2% (0/10) and the Brugada syndrome penetrance around 13% (1/10).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density BrS (%) Penetrance Density LQT3 (%)
NA NA NA 0.458 12 0
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 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.

G1129C 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
1114 15 D1114N, D1114E,
1115 14 W1115R, W1115X,
1116 14 R1116W, R1116Q,
1117 13
1118 13 Q1118X,
1119 12
1120 11
1121 11 A1121V,
1122 10
1123 9
1124 8
1125 8 A1125G, A1125V, A1125T,
1126 7
1127 5
1128 4 C1128X,
1129 0 G1129S,
1130 4 E1130K,
1131 5 c.3390-1G>A, T1131I, T1131S, c.3391-1G>A,
1132 7 P1132S,
1133 8
1134 8 D1134N, D1134E,
1135 9 S1135I,
1136 10 C1136Y,
1137 11
1138 11
1139 12
1140 13 S1140T,
1141 13
1142 14
1143 14
1144 15