SCN5A Variant I1331V Detail

We estimate the penetrance of LQTS for SCN5A I1331V around 30% and the Brugada syndrome penetrance around 8%. SCN5A I1331V was found in a total of 1 carriers in 0 papers and/or in gnomAD: 0 had Brugada syndrome, 0 had LQTS. I1331V is present in 1 alleles in gnomAD. I1331V has been functionally characterized in 0 papers. This residue is located in a Non_Hotspot region for Brugada syndrome and a Hotspot region for LQTS. In silico predictions, functional data (if available), and location in structure are equivalent to phenotyping 10 individuals for Brugada syndrome (0 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 I1331V around 30% (1/11) and the Brugada syndrome penetrance around 8% (0/11).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density BrS (%) Penetrance Density LQT3 (%)
-0.98 0.967 2.02 0.887 6 49
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 14 1 0 - -
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.

I1331V has 45 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 6 V1328M,
1271 14 W1271C,
1765 13
1340 15 V1340I,
1757 10
1472 10 N1472S, p.N1472del,
1339 13 p.L1339del, L1339F,
1756 15 I1756V,
1333 6
1754 13
1270 14 A1270S,
1471 14
1762 8 p.I1762del, I1762M,
1470 15
1464 14 c.4389_4396delCCTCTTTA, L1464P,
1466 14 c.4396_4397insG,
1329 5 G1329S,
1766 11 M1766V, M1766L, M1766T,
1473 13 F1473C, F1473S,
1334 5 I1334V,
1341 14
1468 10 V1468A, V1468F,
1663 14
1759 13 S1759C,
1324 11
1327 6
1758 10 I1758V, p.I1758del,
1330 4 A1330D, A1330P, A1330T,
1323 13 V1323G,
1338 10 L1338V,
1322 15 c.3963+2T>C, c.3963+4A>G,
1337 10
1326 9 A1326S,
1763 12 V1763M, V1763L,
1311 15 L1311P,
1332 4 P1332L, P1332Q,
1465 11 p.F1465_L1480dup,
1467 14
1476 14 Q1476R, Q1476X,
1331 0 I1331V,
1761 11 L1761F, c.5280delG, L1761H,
1469 10 I1469V,
1336 9
1325 11 N1325S,
1335 6 M1335R,