SCN5A Variant G327A Detail

We estimate the penetrance of LQTS for SCN5A G327A around 9% and the Brugada syndrome penetrance around 38%. SCN5A G327A was found in a total of 0 carriers in 0 papers and/or in gnomAD: 0 had Brugada syndrome, 0 had LQTS. G327A is not present in gnomAD. G327A has been functionally characterized in 0 papers. This residue is located in a 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 (3 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 G327A around 9% (0/10) and the Brugada syndrome penetrance around 38% (3/10).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density BrS (%) Penetrance Density LQT3 (%)
NA NA NA 0.94 53 8
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 0 3 - -
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.

G327A has 49 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 4
333 6 c.998+1G>A, c.998+5G>A,
277 12
326 4
276 11 L276P, L276Q,
387 12
348 14 P348A,
279 9
385 7 A385T,
338 13
330 10 S330F,
278 6 H278D, H278R,
388 13 I388S,
334 5 c.999-424_1338+81del,
332 6 A332T,
343 11
327 0
339 11
384 5 S384T,
329 6
1692 14
386 9 G386E, G386R,
340 10 R340W, R340Q,
378 15
331 10
379 13
272 13
341 5 C341Y,
274 12 G274C,
335 7 C335S, C335R,
325 7 L325R,
1690 14 c.5068_5070delGA, D1690N,
324 10
389 12 Y389H, Y389X,
345 15
275 9 N275K,
383 7
280 8 C280Y,
323 11
382 10
337 14
1689 13 D1689N,
342 9
336 10 P336L,
344 12 A344S,
381 10 c.1141-3C>A, c.1140+1G>A,
1691 11
380 11
281 11 V281M,