SCN5A Variant I1350L Detail

We estimate the penetrance of LQTS for SCN5A I1350L around 0% and the Brugada syndrome penetrance around 31%. SCN5A I1350L was found in a total of 1 carriers in 0 papers and/or in gnomAD: 0 had Brugada syndrome, 0 had LQTS. I1350L is present in 1 alleles in gnomAD. I1350L 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 I1350L around 0% (0/11) and the Brugada syndrome penetrance around 31% (3/11).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density BrS (%) Penetrance Density LQT3 (%)
-1.95 0.986 -0.24 0.928 50 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
LITERATURE, COHORT, AND GNOMAD: - 1 1 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.

I1350L has 66 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 10
1403 12
1357 10 A1357V,
811 9 R811G, c.2435_2436+3delTGGTAinsCGCCT, R811H,
733 11 F733L,
741 14 p.M741_T742delinsI ,
808 10 R808C, R808H, R808P,
1352 6
1406 11 G1406E, G1406R,
1453 12
1351 6 M1351V, M1351R,
739 14
1449 11 Y1449C, Y1449S,
1452 14
812 7 L812Q,
1350 0 I1350T, I1350L,
1344 12 F1344S, F1344L,
731 8 T731I,
806 14 V806M,
1450 14
818 14
1411 13
1353 5 V1353M,
1407 11
737 7
1410 14
1358 14 G1358W, G1358R,
1348 8 F1348L,
1404 10
1349 4
749 13
1346 6 L1346I, L1346P,
805 14 S805L,
1359 14 K1359N, K1359M,
1341 15
1356 11 c.4066_4068delTT,
1434 15 Y1434X, c.4299G>A, c.4299+1G>T, c.4299+2T>A, c.4300-1G>A, c.4299+1delG, c.4299delG, c.4299_4300insG, c.4300-2A>T, c.4299+28C>T,
728 14 V728I,
1412 11 L1412F,
810 12
727 14
1408 9 G1408R,
735 6 A735T, A735V, A735E,
732 10
734 6 c.2201dupT, M734V,
814 12 R814Q,
807 15
816 12 F816L, F816Y,
1401 13
813 12 c.2437-5C>A, c.2436+12G>A,
1354 6
738 12
1405 7 V1405M, V1405L,
809 9
1409 11 Y1409C, Y1409X,
815 10
1343 11
1345 11 W1345C,
1342 12
736 9 L736P,
730 11 N730K,
753 13
1347 6
729 14 p.L729del,
1402 10
1413 15