SCN5A Variant A1427S Detail

We estimate the penetrance of LQTS for SCN5A A1427S around 3% and the Brugada syndrome penetrance around 44%. SCN5A A1427S was found in a total of 1 carriers in 1 papers and/or in gnomAD: 1 had Brugada syndrome, 0 had LQTS. A1427S is not present in gnomAD. A1427S has been functionally characterized in 2 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 (3 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 A1427S around 3% (0/11) and the Brugada syndrome penetrance around 44% (4/11).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density BrS (%) Penetrance Density LQT3 (%)
-2.85 0.943 0.31 0.892 52 1
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
20129283 2010 1 0 1 0
LITERATURE, COHORT, AND GNOMAD: - 1 0 0 1 -
VARIANT FEATURES ALONE: - 15 12 0 3 - -
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.

Functional Data

Peak and late/persistent current are relative to wildtype (100% being no different from wildtype). V0.5 act/inact are the voltages at which half of the maximal current is reached during an activation and inactivation protocol, each is in units of mV and relative to wildtype.
PubMed ID Year Cell Type Peak Current (%WT) V1/2 Act. (mV) V1/2 Inact. (mV) Late/Persistent Current (%WT)
20129283 2010
24445991 2014 HEK 16 2.5 0

A1427S has 63 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
1355 12
1403 13
1357 12 A1357V,
1430 5 D1430N,
1352 13
1426 5
1445 14 Y1445H,
1361 9
1447 13
1444 11 L1444I,
1440 10 W1440X,
1382 15 S1382I,
1395 14
1397 11 c.4190delA, c.4189delT,
1449 13 Y1449S, Y1449C,
1380 12 N1380K, p.N1380del,
1429 6
1442 12 Y1442N, Y1442C,
1450 11
1398 8 V1398M,
1411 12
1353 15 V1353M,
1407 14
886 14 H886Q, H886P,
1714 14 D1714G,
1358 11 G1358W, G1358R,
1396 12
1362 7 R1362S, c.4083delG,
1433 11 G1433V, G1433R, G1433W,
1438 8 P1438L,
1423 7 D1423H,
1437 11
1431 6 S1431C,
1422 10 M1422R,
1359 8 K1359N, K1359M,
1356 8 c.4066_4068delTT,
1434 13 c.4299+28C>T, c.4299delG, c.4300-1G>A, c.4299G>A, c.4299+1delG, c.4299+1G>T, c.4299_4300insG, c.4299+2T>A, Y1434X, c.4300-2A>T,
1412 14 L1412F,
1408 13 G1408R,
889 14
1420 11 G1420P, G1420R, G1420D, G1420V,
1360 5 F1360C,
1401 10
1425 7
1399 12
1427 0 A1427E, A1427S,
1446 12
1424 6 I1424V,
1432 11 R1432G, R1432S,
1439 10 Q1439R, Q1439H,
1364 13 I1364V,
878 10 R878L, R878C, R878H,
1400 9 V1400I,
1421 12
1443 11 N1443S,
1441 12 E1441Q,
879 12 W879R,
1415 13
1428 4 A1428S, A1428V,
1363 13 C1363Y,
1436 14
1414 14 Q1414H,
1402 10