SCN5A Variant I1364V Detail

We estimate the penetrance of LQTS for SCN5A I1364V around 2% and the Brugada syndrome penetrance around 19%. SCN5A I1364V was found in a total of 1 carriers in 0 papers and/or in gnomAD: 0 had Brugada syndrome, 0 had LQTS. I1364V is present in 1 alleles in gnomAD. I1364V 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 I1364V around 2% (0/11) and the Brugada syndrome penetrance around 19% (2/11).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density BrS (%) Penetrance Density LQT3 (%)
-0.14 0.326 2.32 0.533 31 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: - 1 1 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.

I1364V has 38 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
1386 10
1394 6 Y1394X,
1430 13 D1430N,
1426 13
1361 8
1382 11 S1382I,
1395 8
1397 10 c.4189delT, c.4190delA,
1390 14
1380 6 N1380K, p.N1380del,
1398 10 V1398M,
1396 5
1362 6 c.4083delG, R1362S,
1438 10 P1438L,
1388 13
1423 15 D1423H,
1387 13 L1387F,
1378 6 V1378M,
1437 10
1431 14 S1431C,
1383 14 Q1383X,
1391 13 G1391R,
1366 7 Q1366H, Q1366R,
1381 9
1360 12 F1360C,
1393 9 L1393X,
1399 13
1427 13 A1427E, A1427S,
1385 13
1365 5 N1365S,
1389 12
1439 13 Q1439R, Q1439H,
1392 13
1364 0 I1364V,
1379 6
1363 4 C1363Y,
1436 15
1367 9