SCN5A Variant G1220A Detail

We estimate the penetrance of LQTS for SCN5A G1220A around 13% and the Brugada syndrome penetrance around 19%. SCN5A G1220A was found in a total of 0 carriers in 0 papers and/or in gnomAD: 0 had Brugada syndrome, 0 had LQTS. G1220A is not present in gnomAD. G1220A has been functionally characterized in 0 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 (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 G1220A around 13% (0/10) and the Brugada syndrome penetrance around 19% (1/10).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density BrS (%) Penetrance Density LQT3 (%)
NA NA NA 0.794 21 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
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.

G1220A has 49 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
1245 14 M1245I,
1218 5 S1218I, S1218T,
1304 12 T1304M,
1217 6
1243 13 D1243N,
1216 7 L1216V,
1234 15
1698 13 A1698T,
1220 0 G1220E,
1673 10
1213 11
1241 14
1309 13 R1309H, R1309C,
1226 12
1669 8
1221 3 A1221V,
1242 11
1668 14 M1668T,
1676 13 M1676T, M1676I,
1219 4 S1219N,
1672 12 S1672Y,
1239 10 L1239P,
1310 11
1306 11 R1306S, R1306H,
1665 12
1305 15
1246 12
1235 11
1701 13 M1701I,
1307 10
1228 14 Y1228H, Y1228F, Y1228C,
1223 5 c.3667delG,
1697 10
1222 5 p.L1222LfsX7, L1222R,
1229 14
1215 9 I1215V,
1301 15
1214 11 M1214T,
1212 13 p.I1212del,
1696 13
1700 14
1308 14 L1308F,
1224 6
1670 12
1240 14 E1240Q,
1225 10 E1225K, G1225K,
1238 12
1303 12 R1303Q, R1303W,
1666 12