SCN5A Variant T1016M Detail

We estimate the penetrance of LQTS for SCN5A T1016M around 2% and the Brugada syndrome penetrance around 8%. SCN5A T1016M was found in a total of 23 carriers in 1 papers and/or in gnomAD: 0 had Brugada syndrome, 0 had LQTS. T1016M is present in 22 alleles in gnomAD. T1016M has been functionally characterized in 1 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 (2 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 T1016M around 2% (0/33) and the Brugada syndrome penetrance around 8% (2/33).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density BrS (%) Penetrance Density LQT3 (%)
-0.12 0.404 0.34 0.249 38 14
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
20129283 2010 1 0 0 0
LITERATURE, COHORT, AND GNOMAD: - 23 23 0 0 -
VARIANT FEATURES ALONE: - 15 13 0 2 - -
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.

Functional Data

Peak and late/persistent current are relative to wildtype (100% being no different from wildtype). V0.5 act/inact are the voltages at which half of the maximal current is reached during an activation and inactivation protocol, each is in units of mV and relative to wildtype.
PubMed ID Year Cell Type Peak Current (%WT) V1/2 Act. (mV) V1/2 Inact. (mV) Late/Persistent Current (%WT)
20129283 2010

T1016M 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
1001 15
1002 14 P1002S, c.3005-3012delCCAGCTGG,
1003 14
1004 13 C1004R,
1005 13 I1005V, I1005T,
1006 12 A1006S,
1007 11 T1007I, T1007N,
1008 11 P1008S,
1009 10
1010 9
1011 8 P1011L, P1011S,
1012 8
1013 7
1014 5 P1014S,
1015 4 p.G1015DfsX14, E1015K,
1016 0 T1016M, c.3045_3046delGA,
1017 4
1018 5 K1018E,
1019 7
1020 8
1021 8 P1021S,
1022 9
1023 10 R1023P, R1023H, R1023C,
1024 11 K1024R,
1025 11 E1025A,
1026 12
1027 13 R1027P, R1027Q, R1027W,
1028 13
1029 14 E1029K,
1030 14
1031 15 p.G1031fsX27,