SCN5A Variant K830Q Detail

We estimate the penetrance of LQTS for SCN5A K830Q around 33% and the Brugada syndrome penetrance around 15%. SCN5A K830Q was found in a total of 0 carriers in 0 papers and/or in gnomAD: 0 had Brugada syndrome, 0 had LQTS. K830Q is not present in gnomAD. K830Q has been functionally characterized in 0 papers. This residue is located in a Mild_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 K830Q around 33% (1/10) and the Brugada syndrome penetrance around 15% (1/10).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density BrS (%) Penetrance Density LQT3 (%)
NA NA NA 0.931 12 43
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.

K830Q has 33 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
839 14 L839P,
821 14
943 13 S943N,
1340 15 V1340I,
780 13
819 11
836 11 V836M,
826 7 N826D,
825 10
781 12 W781X,
822 15 W822C, W822X,
944 11
830 0
833 7 G833R,
940 14 S940N,
831 5
820 12
938 14
823 11 P823T,
942 10
834 6 N834D,
827 6
1460 15 F1460L,
816 15 F816L, F816Y,
837 14
779 15 Q779K, Q779X,
941 11 S941F, S941N,
838 15
824 11
829 6
832 8
835 10 S835A, S835L,
828 8 L828V,