SCN5A Variant I1343L Detail

We estimate the penetrance of LQTS for SCN5A I1343L around 7% and the Brugada syndrome penetrance around 50%. SCN5A I1343L was found in a total of 0 carriers in 0 papers and/or in gnomAD: 0 had Brugada syndrome, 0 had LQTS. I1343L is not present in gnomAD. I1343L 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 (4 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 I1343L around 7% (0/10) and the Brugada syndrome penetrance around 50% (4/10).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density BrS (%) Penetrance Density LQT3 (%)
NA NA NA 0.805 76 5
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 11 0 4 - -
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.

I1343L 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
821 12
1406 14 G1406R, G1406E,
1340 5 V1340I,
1457 12
1453 13
1339 6 L1339F, p.L1339del,
1351 13 M1351R, M1351V,
1461 11 T1461S,
812 11 L812Q,
1350 11 I1350T, I1350L,
1344 5 F1344L, F1344S,
731 10 T731I,
819 9
826 13 N826D,
818 8
825 8
1348 10 F1348L,
1464 14 L1464P, c.4389_4396delCCTCTTTA,
1349 10
822 9 W822X, W822C,
1346 5 L1346I, L1346P,
724 14 T724I,
1341 6
1334 15 I1334V,
1462 14
728 12 V728I,
820 15
1412 13 L1412F,
823 13 P823T,
727 13
1408 14 G1408R,
735 12 A735V, A735T, A735E,
1456 12
732 13
734 13 c.2201dupT, M734V,
827 14
814 14 R814Q,
1460 13 F1460L,
816 9 F816L, F816Y,
813 13 c.2436+12G>A, c.2437-5C>A,
1338 9 L1338V,
817 13 K817E,
1405 12 V1405M, V1405L,
1409 11 Y1409C, Y1409X,
815 8
1343 0
1345 7 W1345C,
1337 10
1342 5
1465 14 p.F1465_L1480dup,
730 14 N730K,
1347 7
1336 11
824 10
829 12
1335 13 M1335R,
832 14
828 11 L828V,
1413 14