SCN5A Variant I1347L Detail

We estimate the penetrance of LQTS for SCN5A I1347L around 4% and the Brugada syndrome penetrance around 46%. SCN5A I1347L was found in a total of 0 carriers in 0 papers and/or in gnomAD: 0 had Brugada syndrome, 0 had LQTS. I1347L is not present in gnomAD. I1347L 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 I1347L around 4% (0/10) and the Brugada syndrome penetrance around 46% (4/10).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density BrS (%) Penetrance Density LQT3 (%)
NA NA NA 0.931 67 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
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.

I1347L has 71 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 13
811 12 R811H, R811G, c.2435_2436+3delTGGTAinsCGCCT,
808 13 R808P, R808H, R808C,
1352 10
1406 14 G1406R, G1406E,
1340 11 V1340I,
1457 11
1453 10
1455 14
1339 12 L1339F, p.L1339del,
1351 6 M1351R, M1351V,
1449 11 Y1449S, Y1449C,
1452 11
1461 13 T1461S,
812 6 L812Q,
1350 6 I1350L, I1350T,
1344 6 F1344L, F1344S,
731 10 T731I,
806 15 V806M,
1450 13
819 12
818 11
1411 14
1451 15 V1451L, V1451D,
1353 11 V1353M,
825 12
1407 15
737 13
1458 15 S1458Y,
1348 5 F1348L,
1404 15
1349 6
822 14 W822C, W822X,
788 15 I788V,
1346 5 L1346P, L1346I,
1341 10
1356 14 c.4066_4068delTT,
728 14 V728I,
1412 11 L1412F,
810 12
727 13
1408 12 G1408R,
735 11 A735E, A735T, A735V,
1456 10
732 13
734 9 c.2201dupT, M734V,
814 11 R814Q,
1460 14 F1460L,
816 7 F816L, F816Y,
813 9 c.2436+12G>A, c.2437-5C>A,
1454 14
1338 15 L1338V,
1354 11
817 13 K817E,
1405 11 V1405M, V1405L,
809 10
1409 11 Y1409C, Y1409X,
815 6
1343 7
1345 8 W1345C,
1342 9
784 14 F784L,
1416 15 c.4245+1G>A, A1416E, A1416G, c.4245+2T>A, c.4245+1G>C,
736 15 L736P,
730 13 N730K,
1347 0
1415 15
829 14
828 14 L828V,
1402 13
1413 14