SCN5A Variant I1670L Detail

We estimate the penetrance of LQTS for SCN5A I1670L around 7% and the Brugada syndrome penetrance around 26%. SCN5A I1670L was found in a total of 0 carriers in 0 papers and/or in gnomAD: 0 had Brugada syndrome, 0 had LQTS. I1670L is not present in gnomAD. I1670L 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 I1670L around 7% (0/10) and the Brugada syndrome penetrance around 26% (2/10).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density BrS (%) Penetrance Density LQT3 (%)
NA NA NA 0.902 33 5
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.

I1670L has 71 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
1271 14 W1271C,
1218 13 S1218I, S1218T,
1304 8 T1304M,
1757 15
1315 15
1274 13
1216 13 L1216V,
1698 14 A1698T,
1756 15 I1756V,
1314 12 c.3940_3941delCT,
1220 12 G1220E,
1673 6
1675 9
1666 6
1754 11
1707 13
1694 13
1704 10 L1704H,
1309 12 R1309H, R1309C,
1226 14
1669 5
1671 5
1221 14 A1221V,
1668 7 M1668T,
1676 10 M1676T, M1676I,
1219 10 S1219N,
1672 6 S1672Y,
1313 14
1660 15 I1660S, I1660V,
1310 9
1306 12 R1306S, R1306H,
1665 9
1305 9
1703 14
1663 10
1302 14 p.L1302Vfs18,
1759 12 S1759C,
1662 13
1327 15
1701 11 M1701I,
1307 6
1758 11 p.I1758del, I1758V,
1678 13 N1678S,
1223 11 c.3667delG,
1755 10
1697 13
1222 11 L1222R, p.L1222LfsX7,
1674 7 F1674V,
1215 13 I1215V,
1708 13 T1708I,
1301 12
1696 15
1705 14
1700 11
1312 15
1763 14 V1763L, V1763M,
1751 10
1311 8 L1311P,
1677 12
1308 7 L1308F,
1750 15 L1750F,
1752 14
1224 15
1670 0
1661 13 G1661R, G1661E,
1225 14 E1225K, G1225K,
1278 14 I1278N,
1679 13
1667 5 V1667I,
1664 11
1303 13 R1303Q, R1303W,