SCN5A Variant V806M Detail

We estimate the penetrance of LQTS for SCN5A V806M around 2% and the Brugada syndrome penetrance around 14%. SCN5A V806M was found in a total of 1 carriers in 0 papers and/or in gnomAD: 0 had Brugada syndrome, 0 had LQTS. V806M is present in 1 alleles in gnomAD. V806M 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 V806M around 2% (0/11) and the Brugada syndrome penetrance around 14% (1/11).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density BrS (%) Penetrance Density LQT3 (%)
-2.97 0.954 -0.6 0.958 14 2
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: - 1 1 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.

V806M has 42 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
1355 10
811 10 R811G, R811H, c.2435_2436+3delTGGTAinsCGCCT,
808 8 R808H, R808P, R808C,
1352 13
1445 13 Y1445H,
1351 10 M1351R, M1351V,
1449 13 Y1449S, Y1449C,
1452 15
812 11 L812Q,
1350 14 I1350T, I1350L,
792 12
791 10 L791F,
806 0 V806M,
1353 14 V1353M,
797 13 G797V,
1348 15 F1348L,
788 14 I788V,
805 4 S805L,
798 9
793 15 L793F,
1356 14 c.4066_4068delTT,
1434 15 c.4299+2T>A, c.4299G>A, c.4299delG, c.4299_4300insG, c.4299+28C>T, c.4300-2A>T, Y1434X, c.4299+1G>T, c.4300-1G>A, c.4299+1delG,
810 6
734 15 M734V, c.2201dupT,
803 10
814 14 R814Q,
807 4
813 12 c.2437-5C>A, c.2436+12G>A,
1354 10
1446 12
1448 14 I1448T, I1448L,
809 5
790 14
1443 15 N1443S,
796 13
802 12
1347 15
795 9
799 12
787 15
794 10
804 6