SCN5A Variant L1666V Detail

We estimate the penetrance of LQTS for SCN5A L1666V around 13% and the Brugada syndrome penetrance around 18%. SCN5A L1666V was found in a total of 0 carriers in 0 papers and/or in gnomAD: 0 had Brugada syndrome, 0 had LQTS. L1666V is not present in gnomAD. L1666V 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 L1666V around 13% (0/10) and the Brugada syndrome penetrance around 18% (1/10).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density BrS (%) Penetrance Density LQT3 (%)
NA NA NA 0.884 17 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.

L1666V has 67 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
1659 11
1271 14 W1271C,
1218 14 S1218I, S1218T,
1304 13 T1304M,
1315 11
1274 14
1216 10 L1216V,
1698 15 A1698T,
1314 7 c.3940_3941delCT,
1220 12 G1220E,
1320 11 M1320I,
1673 10
1675 14
1764 15 V1764F, c.5290delG,
1666 0
1754 15
1707 15
1704 11 L1704H,
1309 12 R1309H, R1309C,
1669 5
1671 9
1762 14 I1762M, p.I1762del,
1221 15 A1221V,
1668 7 M1668T,
1676 15 M1676I, M1676T,
1219 10 S1219N,
1672 10 S1672Y,
1313 10
1660 11 I1660V, I1660S,
1310 7
1766 14 M1766L, M1766V, M1766T,
1306 15 R1306H, R1306S,
1319 15 G1319V,
1665 5
1305 13
1663 6
1759 12 S1759C,
1662 7
1324 12
1317 13 F1317C,
1327 13
1701 11 M1701I,
1307 8
1758 11 I1758V, p.I1758del,
1223 12 c.3667delG,
1755 12
1697 14
1222 13 p.L1222LfsX7, L1222R,
1674 13 F1674V,
1323 13 V1323G,
394 15
1215 12 I1215V,
1708 13 T1708I,
1212 13 p.I1212del,
1705 13
1700 13
1312 13
1763 11 V1763M, V1763L,
1751 15
1311 7 L1311P,
1308 9 L1308F,
1670 6
1661 9 G1661E, G1661R,
398 15
1667 5 V1667I,
1664 7
1658 14