SCN5A Variant G1127V Detail

We estimate the penetrance of LQTS for SCN5A G1127V around 3% and the Brugada syndrome penetrance around 12%. SCN5A G1127V was found in a total of 0 carriers in 0 papers and/or in gnomAD: 0 had Brugada syndrome, 0 had LQTS. G1127V is not present in gnomAD. G1127V 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 G1127V around 3% (0/10) and the Brugada syndrome penetrance around 12% (1/10).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density BrS (%) Penetrance Density LQT3 (%)
NA NA NA 0.578 10 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.

G1127V 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
1112 15 Q1112X,
1113 14 A1113T, A1113V,
1114 14 D1114N, D1114E,
1115 13 W1115R, W1115X,
1116 13 R1116W, R1116Q,
1117 12
1118 11 Q1118X,
1119 11
1120 10
1121 9 A1121V,
1122 8
1123 8
1124 7
1125 5 A1125G, A1125V, A1125T,
1126 4
1127 0
1128 4 C1128X,
1129 5 G1129S,
1130 7 E1130K,
1131 8 c.3390-1G>A, T1131I, T1131S, c.3391-1G>A,
1132 8 P1132S,
1133 9
1134 10 D1134N, D1134E,
1135 11 S1135I,
1136 11 C1136Y,
1137 12
1138 13
1139 13
1140 14 S1140T,
1141 14
1142 15