SCN5A Variant I829V Detail

We estimate the penetrance of LQTS for SCN5A I829V around 42% and the Brugada syndrome penetrance around 12%. SCN5A I829V was found in a total of 0 carriers in 0 papers and/or in gnomAD: 0 had Brugada syndrome, 0 had LQTS. I829V is not present in gnomAD. I829V 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 (2 with LQTS). These data combined with observations of carriers lead us to estimate the LQTS penetrance for SCN5A I829V around 42% (2/10) and the Brugada syndrome penetrance around 12% (1/10).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density BrS (%) Penetrance Density LQT3 (%)
NA NA NA 0.707 9 57
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 12 2 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.

I829V has 47 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
937 15
839 13 L839P,
821 12
1340 10 V1340I,
1457 15
1339 13 p.L1339del, L1339F,
780 13
1461 13 T1461S,
1344 10 F1344S, F1344L,
819 7
836 11 V836M,
826 6 N826D,
818 12
825 6
781 10 W781X,
1464 13 c.4389_4396delCCTCTTTA, L1464P,
822 12 W822C, W822X,
944 14
830 6
833 7 G833R,
1341 13
831 7
820 11
938 14
823 10 P823T,
942 11
1456 12
834 9 N834D,
827 7
1460 11 F1460L,
816 9 F816Y, F816L,
837 14
813 14 c.2437-5C>A, c.2436+12G>A,
817 12 K817E,
815 13
1343 12
941 12 S941N, S941F,
1337 13
784 12 F784L,
838 15
1347 14
1336 14
824 9
829 0
832 5
835 10 S835L, S835A,
828 4 L828V,