SCN5A Variant S1382I Detail

We estimate the penetrance of LQTS for SCN5A S1382I around 1% and the Brugada syndrome penetrance around 37%. SCN5A S1382I was found in a total of 8 carriers in 3 papers and/or in gnomAD: 3 had Brugada syndrome, 0 had LQTS. S1382I is not present in gnomAD. S1382I has been functionally characterized in 4 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 S1382I around 1% (0/18) and the Brugada syndrome penetrance around 37% (6/18).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density BrS (%) Penetrance Density LQT3 (%)
-4.4 0.976 -1.08 0.827 43 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
12106943 2002 1 0 1 0
20031634 2009 8 0 3 0
20129283 2010 1 0 1 0
LITERATURE, COHORT, AND GNOMAD: - 8 5 0 3 -
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
32533946 2020 HEK 4 -3.5
12106943 2002
20031634 2009

S1382I has 34 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
1391 14 G1391R,
1441 12 E1441Q,
1381 4
1396 15
1362 10 R1362S, c.4083delG,
1438 9 P1438L,
1379 9
1386 6
1388 12
1430 11 D1430N,
1426 13
1387 8 L1387F,
1378 14 V1378M,
1437 8
1361 13
1384 7 C1384Y,
1431 14 S1431C,
1395 13
1440 11 W1440X,
1382 0 S1382I,
875 15
1427 15 A1427S, A1427E,
1390 13
1363 9 C1363Y,
1365 11 N1365S,
1385 8
1380 6 N1380K, p.N1380del,
1383 4 Q1383X,
1432 13 R1432S, R1432G,
1389 14
1439 7 Q1439R, Q1439H,
1442 11 Y1442N, Y1442C,
1436 13
1364 11 I1364V,