SCN5A Variant N1374I Detail

We estimate the penetrance of LQTS for SCN5A N1374I around 3% and the Brugada syndrome penetrance around 30%. SCN5A N1374I was found in a total of 0 carriers in 0 papers and/or in gnomAD: 0 had Brugada syndrome, 0 had LQTS. N1374I is not present in gnomAD. N1374I has been functionally characterized in 0 papers. This residue is located in a Mild_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 (2 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 N1374I around 3% (0/10) and the Brugada syndrome penetrance around 30% (2/10).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density BrS (%) Penetrance Density LQT3 (%)
NA NA NA 0.748 40 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 13 0 2 - -
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.

N1374I 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
1359 15 K1359M, K1359N,
1360 14 F1360C,
1361 14
1362 13 R1362S, c.4083delG,
1363 13 C1363Y,
1364 12 I1364V,
1365 11 N1365S,
1366 11 Q1366R, Q1366H,
1367 10
1368 9
1369 8 G1369R, G1369X,
1370 8 D1370G, D1370A,
1371 7
1372 5
1373 4 L1373X, c.4118delT,
1374 0
1375 4 Y1375H,
1376 5
1377 7 I1377M,
1378 8 V1378M,
1379 8
1380 9 N1380K, p.N1380del,
1381 10
1382 11 S1382I,
1383 11 Q1383X,
1384 12 C1384Y,
1385 13
1386 13
1387 14 L1387F,
1388 14
1389 15