SCN5A Variant I1757M Detail

We estimate the penetrance of LQTS for SCN5A I1757M around 28% and the Brugada syndrome penetrance around 11%. SCN5A I1757M was found in a total of 0 carriers in 0 papers and/or in gnomAD: 0 had Brugada syndrome, 0 had LQTS. I1757M is not present in gnomAD. I1757M has been functionally characterized in 0 papers. This residue is located in a Non_Hotspot region for Brugada syndrome and a Mild_Hotspot region for LQTS. In silico predictions, functional data (if available), and location in structure are equivalent to phenotyping 10 individuals for Brugada syndrome (1 diagnosed with Brugada syndrome) and 5 individuals for LQTS (1 with LQTS). These data combined with observations of carriers lead us to estimate the LQTS penetrance for SCN5A I1757M around 28% (1/10) and the Brugada syndrome penetrance around 11% (1/10).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density BrS (%) Penetrance Density LQT3 (%)
NA NA NA 0.833 6 35
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 13 1 1 - -
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.

I1757M 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
1328 14 V1328M,
1417 12
1765 10
1340 14 V1340I,
1457 15
1757 0
1413 11
1339 14 p.L1339del, L1339F,
1756 5 I1756V,
1461 13 T1461S,
1764 11 V1764F, c.5290delG,
1333 12
1754 6
1707 12
1704 14 L1704H,
1458 15 S1458Y,
1410 14
1671 11
1762 6 I1762M, p.I1762del,
1464 13 c.4389_4396delCCTCTTTA, L1464P,
1668 14 M1668T,
1466 13 c.4396_4397insG,
1753 7 T1753A,
1329 14 G1329S,
1766 11 M1766L, M1766V, M1766T,
1334 8 I1334V,
1341 11
1468 13 V1468A, V1468F,
1663 13
1462 10
1759 7 S1759C,
1327 11
1709 13 p.T1709del, T1709R, T1709M,
1758 4 I1758V, p.I1758del,
1755 8
1330 11 A1330P, A1330T, A1330D,
1713 11
1338 8 L1338V,
1748 14 G1748D, p.G1748del,
1708 11 T1708I,
1409 13 Y1409C, Y1409X,
1345 13 W1345C,
1337 11
1342 13
1326 14 A1326S,
1763 9 V1763M, V1763L,
1751 11
1416 13 A1416G, c.4245+1G>C, c.4245+2T>A, A1416E, c.4245+1G>A,
1332 13 P1332L, P1332Q,
1465 8 p.F1465_L1480dup,
1760 7
1467 15
1750 11 L1750F,
1752 11
1670 15
1331 10 I1331V,
1761 5 L1761H, c.5280delG, L1761F,
1749 13 I1749N,
1469 12 I1469V,
1336 14
1710 12 S1710L,
1335 10 M1335R,
1667 12 V1667I,
1414 14 Q1414H,
1664 13
1463 14 N1463Y,