SCN5A Variant A1746G Detail

We estimate the penetrance of LQTS for SCN5A A1746G around 31% and the Brugada syndrome penetrance around 12%. SCN5A A1746G was found in a total of 0 carriers in 0 papers and/or in gnomAD: 0 had Brugada syndrome, 0 had LQTS. A1746G is not present in gnomAD. A1746G 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 A1746G around 31% (1/10) 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 0.639 10 40
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.

A1746G has 38 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
1746 0 A1746T, A1746V,
1724 13
1406 12 G1406E, G1406R,
1745 4
1756 15 I1756V,
1675 13
1743 10 G1743R, G1743E,
1723 12 T1723N,
1754 12
1725 14 P1725L,
1407 13
1410 11
1747 4 V1747M,
1716 15 p.L1716SfsX71,
1671 15
1404 15
1744 6 S1744I,
1721 8
1753 10 T1753A,
1742 13
1719 13
1728 14 C1728W, C1728Y, C1728R,
1678 10 N1678S,
1674 12 F1674V,
1399 15
1748 5 p.G1748del, G1748D,
1409 14 Y1409C, Y1409X,
1718 13 S1718R,
1717 11 L1717P,
1751 9
1677 14
1682 14
1750 5 L1750F,
1752 10
1722 9 N1722D,
1749 5 I1749N,
1720 9 c.5157delC,
1679 11