SCN5A Variant L1750F Detail

We estimate the penetrance of LQTS for SCN5A L1750F around 14% and the Brugada syndrome penetrance around 9%. SCN5A L1750F was found in a total of 1 carriers in 0 papers and/or in gnomAD: 0 had Brugada syndrome, 0 had LQTS. L1750F is present in 1 alleles in gnomAD. L1750F has been functionally characterized in 0 papers. This residue is located in a Non_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 (0 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 L1750F around 14% (0/11) and the Brugada syndrome penetrance around 9% (0/11).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density BrS (%) Penetrance Density LQT3 (%)
1.71 0.302 3.17 0.541 9 24
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: - 1 1 0 0 -
VARIANT FEATURES ALONE: - 15 15 0 0 - -
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.

L1750F has 37 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 5 A1746T, A1746V,
1406 13 G1406E, G1406R,
1757 11
1745 9
1756 11 I1756V,
1675 12
1743 14 G1743R, G1743E,
1754 6
1707 14
1407 14
1410 11
1747 6 V1747M,
1716 15 p.L1716SfsX71,
1671 11
1744 10 S1744I,
1721 11
1753 6 T1753A,
1758 12 I1758V, p.I1758del,
1678 11 N1678S,
1755 11
1674 10 F1674V,
1713 13
1338 15 L1338V,
1748 5 p.G1748del, G1748D,
1409 12 Y1409C, Y1409X,
1718 15 S1718R,
1717 11 L1717P,
1751 7
1677 14
1750 0 L1750F,
1752 8
1722 13 N1722D,
1670 15
1749 5 I1749N,
1720 11 c.5157delC,
1679 12
1413 13