SCN5A Variant I1049L Detail

We estimate the penetrance of LQTS for SCN5A I1049L around 3% and the Brugada syndrome penetrance around 18%. SCN5A I1049L was found in a total of 0 carriers in 0 papers and/or in gnomAD: 0 had Brugada syndrome, 0 had LQTS. I1049L is not present in gnomAD. I1049L has been functionally characterized in 0 papers. This residue is located in a Mild_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 I1049L around 3% (0/10) and the Brugada syndrome penetrance around 18% (1/10).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density BrS (%) Penetrance Density LQT3 (%)
NA NA NA 0.689 20 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.

I1049L 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
1034 15 P1034T,
1035 14 G1035V,
1036 14
1037 13
1038 13
1039 12
1040 11 G1040R,
1041 11 D1041N, D1041G,
1042 10
1043 9 E1043K,
1044 8
1045 8 V1045M,
1046 7
1047 5 c.3140_3141dupTG,
1048 4 P1048S, p.P1048SfsX96, c.3142_3143insTG,
1049 0
1050 4 p.A1050CfsX9, p.A1050DfsX9, A1050T,
1051 5 V1051A,
1052 7 A1052D, p.A1052CfsX7,
1053 8 E1053K,
1054 8
1055 9 D1055G,
1056 10 T1056A,
1057 11
1058 11 c.3171_3172delTGinsA,
1059 12 Q1059X,
1060 13
1061 13 E1061D,
1062 14 D1062H,
1063 14 E1063G,
1064 15 p.E1064del,