SCN5A Variant L1342I Detail

We estimate the penetrance of LQTS for SCN5A L1342I around 10% and the Brugada syndrome penetrance around 38%. SCN5A L1342I was found in a total of 0 carriers in 0 papers and/or in gnomAD: 0 had Brugada syndrome, 0 had LQTS. L1342I is not present in gnomAD. L1342I has been functionally characterized in 0 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 L1342I around 10% (0/10) and the Brugada syndrome penetrance around 38% (3/10).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density BrS (%) Penetrance Density LQT3 (%)
NA NA NA 0.854 55 10
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 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.

L1342I has 59 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
1406 11 G1406R, G1406E,
1340 7 V1340I,
1457 12
1453 12
1757 13
1339 6 p.L1339del, L1339F,
1351 14 M1351V, M1351R,
1756 14 I1756V,
1461 10 T1461S,
812 14 L812Q,
1350 12 I1350T, I1350L,
1333 15
1344 7 F1344S, F1344L,
731 12 T731I,
1754 15
819 14
818 12
1411 13
825 12
1407 13
1458 14 S1458Y,
1410 12
1348 11 F1348L,
1404 15
1464 14 c.4389_4396delCCTCTTTA, L1464P,
1349 10
1753 13 T1753A,
822 12 W822C, W822X,
1346 5 L1346I, L1346P,
1341 5
1334 13 I1334V,
1462 13
728 14 V728I,
1412 11 L1412F,
1408 12 G1408R,
735 12 A735V, A735T, A735E,
1456 14
732 13
734 14 M734V, c.2201dupT,
1460 14 F1460L,
816 13 F816Y, F816L,
1338 7 L1338V,
1405 10 V1405M, V1405L,
1409 7 Y1409X, Y1409C,
815 12
1343 5
1345 5 W1345C,
1337 9
1342 0
1416 13 A1416G, c.4245+2T>A, c.4245+1G>C, c.4245+1G>A, A1416E,
1465 13 p.F1465_L1480dup,
1761 14 c.5280delG, L1761H, L1761F,
1347 9
1336 11
1415 15
824 13
1335 11 M1335R,
828 14 L828V,
1413 10