SCN5A Variant I1455N Detail

We estimate the penetrance of LQTS for SCN5A I1455N around 23% and the Brugada syndrome penetrance around 33%. SCN5A I1455N was found in a total of 0 carriers in 0 papers and/or in gnomAD: 0 had Brugada syndrome, 0 had LQTS. I1455N is not present in gnomAD. I1455N has been functionally characterized in 0 papers. This residue is located in a 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 (3 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 I1455N around 23% (1/10) and the Brugada syndrome penetrance around 33% (3/10).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density BrS (%) Penetrance Density LQT3 (%)
NA NA NA 0.948 44 28
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 1 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.

I1455N has 67 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
891 15 I891N, I891T,
888 13
848 15 I848F,
896 10 C896S,
937 13
895 11 L895F,
1417 14
839 10 L839P,
842 11
1340 15 V1340I,
1457 6
1453 7
1455 0
1447 12
1351 14 M1351R, M1351V,
1449 11 Y1449C, Y1449S,
1452 6
1461 9 T1461S,
926 14
1344 11 F1344L, F1344S,
1450 10
836 13 V836M,
1451 6 V1451L, V1451D,
934 9
1458 7 S1458Y,
933 14
935 13 L935P,
897 15 G897R, G897E,
1348 10 F1348L,
1464 13 c.4389_4396delCCTCTTTA, L1464P,
927 14 N927K, N927S,
845 13 c.2533delG,
1418 12
892 9 F892I,
849 15
1341 13
1462 11
938 13
1412 13 L1412F,
840 11
889 14
843 8 T843A,
1456 4
930 12 c.2788-6C>T, c.2787+17_2787+18insACACACACACACACACACACACA,
1459 5 c.4376_4379delTCTT,
1460 8 F1460L,
1425 15
837 15
1454 5
1448 10 I1448T, I1448L,
841 14 N841K, p.N841TfsX2,
1421 14
847 11
1345 12 W1345C,
846 10 L846R,
1416 10 c.4245+1G>C, A1416E, c.4245+1G>A, c.4245+2T>A, A1416G,
838 14
1347 14
1415 11
844 12 L844RfsX3,
850 13 V850M, c.2549_2550insTG,
932 15
832 13
835 14 S835A, S835L,
931 10
1463 11 N1463Y,
1413 15