SCN5A Variant D1226G Detail

We estimate the penetrance of LQTS for SCN5A D1226G around 10% and the Brugada syndrome penetrance around 35%. SCN5A D1226G was found in a total of 0 carriers in 0 papers and/or in gnomAD: 0 had Brugada syndrome, 0 had LQTS. D1226G is not present in gnomAD. D1226G has been functionally characterized in 0 papers. This residue is located in a 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 (3 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 D1226G around 10% (0/10) and the Brugada syndrome penetrance around 35% (3/10).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density BrS (%) Penetrance Density LQT3 (%)
NA NA NA 0.979 48 9
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 12 0 3 - -
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.

D1226G has 56 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
1233 14 K1233E,
1218 14 S1218I, S1218T,
1304 11 T1304M,
1243 15 D1243N,
1234 14
1698 11 A1698T,
1299 14 c.3894delC,
1220 12 G1220E,
1673 8
1675 9
1681 10 Y1681F, c.5040_5042delTTAinsC,
1694 10
1226 0
1695 8 Q1695X,
1669 12
1671 15
1221 10 A1221V,
1676 5 M1676I, M1676T,
1219 13 S1219N,
1672 9 S1672Y,
1693 11
1699 11
1239 10 L1239P,
1306 15 R1306S, R1306H,
1680 8 A1680T, A1680P,
1703 15
1235 10
1302 14 p.L1302Vfs18,
1231 11 E1231K,
1237 15 V1237F,
1701 13 M1701I,
1307 14
1228 7 Y1228F, Y1228H, Y1228C,
1678 10 N1678S,
1223 7 c.3667delG,
1697 9
1222 8 p.L1222LfsX7, L1222R,
1230 10 E1230K,
1227 5
1300 12
1674 11 F1674V,
1229 7
1301 10
1696 7
1700 10
1677 7
1682 13
1224 8
1670 14
1240 13 E1240Q,
1740 14 G1740R,
1225 4 G1225K, E1225K,
1238 14
1679 11
1236 11 K1236N, K1236R,
1303 11 R1303W, R1303Q,