SCN5A Variant V1398M Detail

We estimate the penetrance of LQTS for SCN5A V1398M around 5% and the Brugada syndrome penetrance around 17%. SCN5A V1398M was found in a total of 2 carriers in 0 papers and/or in gnomAD: 0 had Brugada syndrome, 0 had LQTS. V1398M is present in 2 alleles in gnomAD. V1398M 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 V1398M around 5% (0/12) and the Brugada syndrome penetrance around 17% (2/12).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density BrS (%) Penetrance Density LQT3 (%)
-2.74 0.948 -2.66 0.827 22 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: - 2 2 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.

V1398M has 65 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
1403 9
1357 12 A1357V,
1724 13
1394 14 Y1394X,
1430 11 D1430N,
1352 15
1426 11
1406 14 G1406E, G1406R,
1715 14
1361 7
739 12
1395 11
1397 5 c.4189delT, c.4190delA,
1380 13 N1380K, p.N1380del,
1429 13
1723 10 T1723N,
1725 13 P1725L,
1398 0 V1398M,
1411 11
1353 15 V1353M,
1407 11
1410 13
1714 11 D1714G,
1358 10 G1358W, G1358R,
1396 7
1433 13 G1433R, G1433W, G1433V,
1362 7 c.4083delG, R1362S,
1438 11 P1438L,
1404 12
1423 9 D1423H,
1378 12 V1378M,
1437 13
1721 13
1431 11 S1431C,
1422 14 M1422R,
1359 10 K1359N, K1359M,
1356 11 c.4066_4068delTT,
1434 14 Y1434X, c.4299G>A, c.4299+1G>T, c.4299+2T>A, c.4300-1G>A, c.4299+1delG, c.4299delG, c.4299_4300insG, c.4300-2A>T, c.4299+28C>T,
1412 14 L1412F,
1719 14
1366 14 Q1366H, Q1366R,
1408 12 G1408R,
1420 12 G1420V, G1420D, G1420R, G1420P,
1360 5 F1360C,
1401 6
1425 13
1399 5
1427 8 A1427E, A1427S,
1424 8 I1424V,
1365 15 N1365S,
738 15
1364 10 I1364V,
1400 5 V1400I,
1718 11 S1718R,
1421 15
1717 14 L1717P,
1379 15
1722 14 N1722D,
1686 14
1415 15
1428 10 A1428V, A1428S,
1363 12 C1363Y,
1685 14
1414 13 Q1414H,
1402 10