SCN5A Variant N1388I Detail

We estimate the penetrance of LQTS for SCN5A N1388I around 3% and the Brugada syndrome penetrance around 12%. SCN5A N1388I was found in a total of 0 carriers in 0 papers and/or in gnomAD: 0 had Brugada syndrome, 0 had LQTS. N1388I is not present in gnomAD. N1388I has been functionally characterized in 0 papers. This residue is located in a Non_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 (1 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 N1388I around 3% (0/10) and the Brugada syndrome penetrance around 12% (1/10).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density BrS (%) Penetrance Density LQT3 (%)
NA NA NA 0.692 9 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: - 0 0 0 0 -
VARIANT FEATURES ALONE: - 15 14 0 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.

N1388I has 37 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
1434 12 c.4299G>A, c.4299+1delG, c.4300-2A>T, c.4299+28C>T, c.4299_4300insG, c.4299+2T>A, c.4300-1G>A, c.4299+1G>T, c.4299delG, Y1434X,
1391 8 G1391R,
1381 12
1358 13 G1358W, G1358R,
1396 12
1362 12 R1362S, c.4083delG,
1433 10 G1433R, G1433V, G1433W,
1438 9 P1438L,
1435 6
1386 7
1394 13 Y1394X,
1360 15 F1360C,
1388 0
1430 14 D1430N,
1393 12 L1393X,
1387 5 L1387F,
1437 7
1361 9
1384 10 C1384Y,
1431 13 S1431C,
1395 7
1382 12 S1382I,
1397 15 c.4189delT, c.4190delA,
1390 6
1363 8 C1363Y,
1365 14 N1365S,
1385 10
1380 13 N1380K, p.N1380del,
1383 12 Q1383X,
1432 10 R1432G, R1432S,
1389 4
1439 12 Q1439H, Q1439R,
1442 15 Y1442N, Y1442C,
1392 12
1436 6
1364 13 I1364V,
1359 13 K1359M, K1359N,