SCN5A Variant D331G Detail

We estimate the penetrance of LQTS for SCN5A D331G around 18% and the Brugada syndrome penetrance around 22%. SCN5A D331G was found in a total of 0 carriers in 0 papers and/or in gnomAD: 0 had Brugada syndrome, 0 had LQTS. D331G is not present in gnomAD. D331G has been functionally characterized in 0 papers. This residue is located in a Mild_Hotspot region for Brugada syndrome and a Mild_Hotspot region for LQTS. In silico predictions, functional data (if available), and location in structure are equivalent to phenotyping 10 individuals for Brugada syndrome (2 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 D331G around 18% (0/10) and the Brugada syndrome penetrance around 22% (2/10).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density BrS (%) Penetrance Density LQT3 (%)
NA NA NA 0.567 28 22
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 0 2 - -
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.

D331G has 44 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
328 10
333 6 c.998+1G>A, c.998+5G>A,
1702 10
326 12
387 5
385 10 A385T,
391 15
330 4 S330F,
388 9 I388S,
1698 8 A1698T,
334 8 c.999-424_1338+81del,
332 5 A332T,
1694 14
327 10
1695 12 Q1695X,
384 11 S384T,
1688 15
329 6
1692 10
386 8 G386R, G386E,
1693 10
378 13
1699 8
331 0
379 14
1703 14
1231 15 E1231K,
335 12 C335R, C335S,
1701 13 M1701I,
325 14 L325R,
1228 11 Y1228H, Y1228C, Y1228F,
1690 11 D1690N, c.5068_5070delGA,
1697 11
389 12 Y389X, Y389H,
1227 14
390 12
383 10
382 9
1696 9
1689 12 D1689N,
1700 12
1224 14
381 13 c.1140+1G>A, c.1141-3C>A,
1691 7