SCN5A Variant I1673M Detail

We estimate the penetrance of LQTS for SCN5A I1673M around 4% and the Brugada syndrome penetrance around 27%. SCN5A I1673M was found in a total of 0 carriers in 0 papers and/or in gnomAD: 0 had Brugada syndrome, 0 had LQTS. I1673M is not present in gnomAD. I1673M 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 (2 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 I1673M around 4% (0/10) and the Brugada syndrome penetrance around 27% (2/10).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density BrS (%) Penetrance Density LQT3 (%)
NA NA NA 0.793 35 1
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 13 0 2 - -
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.

I1673M has 64 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
1702 14
1218 11 S1218T, S1218I,
1304 6 T1304M,
1217 15
1243 15 D1243N,
1216 13 L1216V,
1698 11 A1698T,
1220 10 G1220E,
1673 0
1675 6
1754 15
1694 10
1704 11 L1704H,
1309 14 R1309H, R1309C,
1226 8
1747 14 V1747M,
1695 13 Q1695X,
1669 6
1671 8
1221 10 A1221V,
1668 10 M1668T,
1676 5 M1676I, M1676T,
1219 9 S1219N,
1672 4 S1672Y,
1699 13
1693 14
1239 13 L1239P,
1310 12
1306 11 R1306S, R1306H,
1665 12
1305 10
1680 12 A1680P, A1680T,
1703 13
1235 15
1302 12 p.L1302Vfs18,
1701 10 M1701I,
1307 7
1228 14 Y1228H, Y1228C, Y1228F,
1678 9 N1678S,
1223 7 c.3667delG,
1755 13
1697 9
1222 7 p.L1222LfsX7, L1222R,
1227 12
1300 13
1674 6 F1674V,
1229 13
1215 14 I1215V,
1301 9
1696 10
1700 9
1751 11
1311 14 L1311P,
1677 7
1308 10 L1308F,
1752 15
1224 10
1670 6
1225 8 G1225K, E1225K,
1278 15 I1278N,
1679 10
1667 11 V1667I,
1303 10 R1303Q, R1303W,
1666 10