SCN5A Variant L1663Q Detail

We estimate the penetrance of LQTS for SCN5A L1663Q around 8% and the Brugada syndrome penetrance around 34%. SCN5A L1663Q was found in a total of 0 carriers in 0 papers and/or in gnomAD: 0 had Brugada syndrome, 0 had LQTS. L1663Q is not present in gnomAD. L1663Q 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 L1663Q around 8% (0/10) and the Brugada syndrome penetrance around 34% (3/10).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density BrS (%) Penetrance Density LQT3 (%)
NA NA NA 0.932 46 6
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.

L1663Q has 70 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
1328 12 V1328M,
1659 7
1271 14 W1271C,
1765 13
1757 13
1315 10
1216 15 L1216V,
1756 15 I1756V,
1314 7 c.3940_3941delCT,
1320 7 M1320I,
1764 10 c.5290delG, V1764F,
1666 6
1754 14
1707 15
1656 11
1704 13 L1704H,
1669 11
1671 11
1762 10 I1762M, p.I1762del,
1668 9 M1668T,
1672 14 S1672Y,
1767 10 Y1767C,
1313 11
1660 5 I1660S, I1660V,
1310 11
1769 14
402 13 F402L,
1766 9 M1766T, M1766V, M1766L,
1319 11 G1319V,
1665 8
1768 14 I1768V,
1473 14 F1473C, F1473S,
1663 0
1657 11
1759 9 S1759C,
1662 6
1324 9
1317 11 F1317C,
1327 9
1709 15 T1709R, T1709M, p.T1709del,
1701 14 M1701I,
1307 13
1758 9 p.I1758del, I1758V,
1755 11
1318 14
1330 14 A1330T, A1330P, A1330D,
1321 14 R1321K,
1323 8 V1323G,
394 14
1770 13 I1770V,
1708 11 T1708I,
1705 13
1322 12 c.3963+2T>C, c.3963+4A>G,
1312 13
1326 12 A1326S,
1763 7 V1763L, V1763M,
1311 9 L1311P,
1308 13 L1308F,
1760 14
1670 10
1661 5 G1661R, G1661E,
1331 14 I1331V,
1761 14 c.5280delG, L1761H, L1761F,
1655 13
1469 14 I1469V,
1325 13 N1325S,
398 12
1667 6 V1667I,
1664 5
1658 11