SCN5A Variant I1005T Detail

We estimate the penetrance of LQTS for SCN5A I1005T around 4% and the Brugada syndrome penetrance around 7%. SCN5A I1005T was found in a total of 1 carriers in 0 papers and/or in gnomAD: 0 had Brugada syndrome, 0 had LQTS. I1005T is present in 1 alleles in gnomAD. I1005T 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 (0 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 I1005T around 4% (0/11) and the Brugada syndrome penetrance around 7% (0/11).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density BrS (%) Penetrance Density LQT3 (%)
-1.45 0 0.14 0.319 3 2
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 15 0 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.

I1005T has 31 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
990 15
991 14 K991E, K991T,
992 14
993 13 A993T, A993S,
994 13 A994V, A994T,
995 12 L995F,
996 11 A996T,
997 11 A997S, A997D, A997T,
998 10
999 9 G999D,
1000 8 p.Gln1000del, Q1000L, Q1000X,
1001 8
1002 7 P1002S, c.3005-3012delCCAGCTGG,
1003 5
1004 4 C1004R,
1005 0 I1005V, I1005T,
1006 4 A1006S,
1007 5 T1007I, T1007N,
1008 7 P1008S,
1009 8
1010 8
1011 9 P1011L, P1011S,
1012 10
1013 11
1014 11 P1014S,
1015 12 p.G1015DfsX14, E1015K,
1016 13 T1016M, c.3045_3046delGA,
1017 13
1018 14 K1018E,
1019 14
1020 15