SCN5A Variant L1373M Detail

We estimate the penetrance of LQTS for SCN5A L1373M around 3% and the Brugada syndrome penetrance around 46%. SCN5A L1373M was found in a total of 0 carriers in 0 papers and/or in gnomAD: 0 had Brugada syndrome, 0 had LQTS. L1373M is not present in gnomAD. L1373M 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 L1373M around 3% (0/10) and the Brugada syndrome penetrance around 46% (4/10).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density BrS (%) Penetrance Density LQT3 (%)
NA NA NA 0.563 71 0
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.

L1373M has 31 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
1358 15 G1358W, G1358R,
1359 14 K1359M, K1359N,
1360 14 F1360C,
1361 13
1362 13 R1362S, c.4083delG,
1363 12 C1363Y,
1364 11 I1364V,
1365 11 N1365S,
1366 10 Q1366R, Q1366H,
1367 9
1368 8
1369 8 G1369X, G1369R,
1370 7 D1370A, D1370G,
1371 5
1372 4
1373 0 L1373X, c.4118delT,
1374 4
1375 5 Y1375H,
1376 7
1377 8 I1377M,
1378 8 V1378M,
1379 9
1380 10 N1380K, p.N1380del,
1381 11
1382 11 S1382I,
1383 12 Q1383X,
1384 13 C1384Y,
1385 13
1386 14
1387 14 L1387F,
1388 15