SCN5A Variant Q1491L Detail

We estimate the penetrance of LQTS for SCN5A Q1491L around 41% and the Brugada syndrome penetrance around 11%. SCN5A Q1491L was found in a total of 0 carriers in 0 papers and/or in gnomAD: 0 had Brugada syndrome, 0 had LQTS. Q1491L is not present in gnomAD. Q1491L has been functionally characterized in 0 papers. This residue is located in a Mild_Hotspot region for Brugada syndrome and a 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 (2 with LQTS). These data combined with observations of carriers lead us to estimate the LQTS penetrance for SCN5A Q1491L around 41% (2/10) and the Brugada syndrome penetrance around 11% (1/10).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density BrS (%) Penetrance Density LQT3 (%)
NA NA NA 0.946 5 54
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 2 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.

Q1491L has 44 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
1785 12
1879 14
1486 6 p.F1486del, F1486L,
1866 14
1777 14 V1777L, V1777M,
1485 9
1487 10 M1487L, M1487K,
1492 6
1875 10 p.M1875dup, M1875T, M1875K,
1872 12 K1872N,
1491 0 Q1491H,
1501 15 L1501V, p.L1501_K1505del,
1874 10
1862 12
1493 7 K1493R, K1493X, p.K1493del,
1858 15
1873 14 I1873V,
1865 15
1478 13 K1478E,
1786 14 L1786R, L1786Q, c.5356_5357delCT,
1495 7 Y1495S,
1878 14
1496 9
1481 13 G1481R, G1481E, G1481V,
1781 12 E1781G, E1781D,
1499 12
1877 13 E1877K,
1488 6 T1488R,
1784 11 E1784X, E1784K,
1498 10 M1498V, M1498R, M1498T,
1780 13 E1780G,
1500 14 p.K1500del,
1859 14
1869 11
1876 10
1482 11
1868 11
1783 14
1484 12
1497 10
1490 6
1483 9 Q1483H,
1494 6
1489 8 E1489D,