SCN5A Variant L1717I Detail

We estimate the penetrance of LQTS for SCN5A L1717I around 4% and the Brugada syndrome penetrance around 45%. SCN5A L1717I was found in a total of 0 carriers in 0 papers and/or in gnomAD: 0 had Brugada syndrome, 0 had LQTS. L1717I is not present in gnomAD. L1717I 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 (4 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 L1717I around 4% (0/10) and the Brugada syndrome penetrance around 45% (4/10).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density BrS (%) Penetrance Density LQT3 (%)
NA NA NA 0.829 67 1
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 11 0 4 - -
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.

L1717I 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
1746 11 A1746T, A1746V,
1417 12
1406 14 G1406E, G1406R,
1715 6
1687 10
1745 10
1756 11 I1756V,
1675 13
1743 11 G1743E, G1743R,
1711 11 c.5131delG,
1723 12 T1723N,
1754 13
1707 10
1398 14 V1398M,
1694 12
1411 11
1407 12
1704 13 L1704H,
1410 9
1706 12 Q1706H,
1747 10 V1747M,
1716 5 p.L1716SfsX71,
1714 5 D1714G,
1688 11
1684 15 W1684R,
1671 14
1423 14 D1423H,
1692 14
1744 9 S1744I,
1721 6
1753 10 T1753A,
1693 14
1712 8 G1712C, G1712S,
1680 15 A1680T, A1680P,
1703 12
1412 14 L1412F,
1719 6
1408 14 G1408R,
1709 15 T1709R, T1709M, p.T1709del,
1420 11 G1420R, G1420D, G1420V, G1420P,
1678 14 N1678S,
1755 12
1401 13
1399 9
1713 7
1424 14 I1424V,
1748 7 p.G1748del, G1748D,
1708 14 T1708I,
1683 13
1409 14 Y1409C, Y1409X,
1400 10 V1400I,
1718 5 S1718R,
1700 15
1717 0 L1717P,
1751 9
1416 15 c.4245+1G>A, c.4245+2T>A, c.4245+1G>C, A1416G, A1416E,
1682 12
1750 11 L1750F,
1752 6
1722 10 N1722D,
1686 9
1749 8 I1749N,
375 13
1710 12 S1710L,
1720 5 c.5157delC,
1415 14
1679 11
1685 10
1419 11 K1419E,
1414 9 Q1414H,
1413 11