SCN5A Variant Q1118H Detail

We estimate the penetrance of LQTS for SCN5A Q1118H around 8% and the Brugada syndrome penetrance around 7%. SCN5A Q1118H was found in a total of 0 carriers in 0 papers and/or in gnomAD: 0 had Brugada syndrome, 0 had LQTS. Q1118H is not present in gnomAD. Q1118H has been functionally characterized in 0 papers. This residue is located in a Non_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 (0 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 Q1118H around 8% (0/10) and the Brugada syndrome penetrance around 7% (0/10).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density BrS (%) Penetrance Density LQT3 (%)
NA NA NA 0.433 2 8
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 15 0 0 - -
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.

Q1118H 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
1103 15 S1103F, S1103Y,
1104 14
1105 14 E1105V, E1105X,
1106 13 A1106T,
1107 13 E1107X, p.E1107RfsX24, E1107K,
1108 12
1109 11 S1109G,
1110 11
1111 10
1112 9 Q1112X,
1113 8 A1113T, A1113V,
1114 8 D1114E, D1114N,
1115 7 W1115X, W1115R,
1116 5 R1116W, R1116Q,
1117 4
1118 0 Q1118X,
1119 4
1120 5
1121 7 A1121V,
1122 8
1123 8
1124 9
1125 10 A1125G, A1125V, A1125T,
1126 11
1127 11
1128 12 C1128X,
1129 13 G1129S,
1130 13 E1130K,
1131 14 c.3391-1G>A, c.3390-1G>A, T1131S, T1131I,
1132 14 P1132S,
1133 15