SCN5A Variant T827I Detail

We estimate the penetrance of LQTS for SCN5A T827I around 31% and the Brugada syndrome penetrance around 11%. SCN5A T827I was found in a total of 0 carriers in 0 papers and/or in gnomAD: 0 had Brugada syndrome, 0 had LQTS. T827I is not present in gnomAD. T827I has been functionally characterized in 0 papers. This residue is located in a Non_Hotspot region for Brugada syndrome and a 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 (1 with LQTS). These data combined with observations of carriers lead us to estimate the LQTS penetrance for SCN5A T827I around 31% (1/10) and the Brugada syndrome penetrance around 11% (1/10).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density BrS (%) Penetrance Density LQT3 (%)
NA NA NA 0.748 7 41
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 13 1 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.

T827I has 39 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
821 12
943 12 S943N,
1340 11 V1340I,
1339 12 L1339F, p.L1339del,
1461 15 T1461S,
1333 13
1344 13 F1344L, F1344S,
819 9
826 5 N826D,
818 14
825 7
781 13 W781X,
1464 13 c.4389_4396delCCTCTTTA, L1464P,
822 11 W822C, W822X,
944 9
830 6
833 11 G833R,
940 15 S940N,
1341 14
1468 14 V1468F, V1468A,
831 6
820 12
938 14
823 7 P823T,
942 9
834 11 N834D,
827 0
1460 13 F1460L,
816 14 F816L, F816Y,
1343 14
941 11 S941F, S941N,
1337 12
1467 15
1336 10
824 6
829 7
832 9
835 13 S835A, S835L,
828 5 L828V,