SCN5A Variant L1662Q Detail

We estimate the penetrance of LQTS for SCN5A L1662Q around 7% and the Brugada syndrome penetrance around 37%. SCN5A L1662Q was found in a total of 0 carriers in 0 papers and/or in gnomAD: 0 had Brugada syndrome, 0 had LQTS. L1662Q is not present in gnomAD. L1662Q 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 L1662Q around 7% (0/10) and the Brugada syndrome penetrance around 37% (3/10).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density BrS (%) Penetrance Density LQT3 (%)
NA NA NA 0.95 51 4
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.

L1662Q has 52 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 5
1653 14
1315 11
1216 13 L1216V,
1314 6 c.3940_3941delCT,
1320 7 M1320I,
1764 13 c.5290delG, V1764F,
1666 7
1656 9
1669 11
1668 10 M1668T,
1219 15 S1219N,
1767 11 Y1767C,
1313 10
1660 7 I1660S, I1660V,
1654 12
1310 11
1316 14 R1316Q, R1316L,
402 14 F402L,
1766 12 M1766T, M1766V, M1766L,
1319 10 G1319V,
1665 6
1663 6
399 14
1657 10
1759 14 S1759C,
1662 0
1324 12
1317 8 F1317C,
1327 14
1701 14 M1701I,
1307 14
1758 15 p.I1758del, I1758V,
1318 12
1321 13 R1321K,
1323 10 V1323G,
394 12
1770 14 I1770V,
1708 14 T1708I,
1212 14 p.I1212del,
1705 14
1322 13 c.3963+2T>C, c.3963+4A>G,
1312 14
1763 11 V1763L, V1763M,
1311 11 L1311P,
1670 13
1661 4 G1661R, G1661E,
1655 10
398 11
1667 10 V1667I,
1664 7
1658 7