SCN5A Variant C326G Detail

We estimate the penetrance of LQTS for SCN5A C326G around 7% and the Brugada syndrome penetrance around 47%. SCN5A C326G was found in a total of 0 carriers in 0 papers and/or in gnomAD: 0 had Brugada syndrome, 0 had LQTS. C326G is not present in gnomAD. C326G 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 (4 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 C326G around 7% (0/10) and the Brugada syndrome penetrance around 47% (4/10).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density BrS (%) Penetrance Density LQT3 (%)
NA NA NA 0.96 68 5
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 11 0 4 - -
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.

C326G has 55 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 8
333 6 c.998+1G>A, c.998+5G>A,
277 13
326 0
276 11 L276P, L276Q,
387 14
348 13 P348A,
279 8
385 9 A385T,
338 12
330 12 S330F,
278 7 H278R, H278D,
334 5 c.999-424_1338+81del,
332 7 A332T,
343 13
327 4
339 9
384 6 S384T,
1684 15 W1684R,
329 9
282 13 R282C, R282H,
1692 13
386 11 G386R, G386E,
340 11 R340W, R340Q,
378 15
331 12
283 14
379 12
272 15
341 6 C341Y,
274 13 G274C,
335 5 C335R, C335S,
325 5 L325R,
1690 12 D1690N, c.5068_5070delGA,
324 7
321 13 S321Y,
389 15 Y389H, Y389X,
345 14
275 11 N275K,
383 5
280 5 C280Y,
323 8
347 14
382 11
337 13
320 14 T320N,
1689 11 D1689N,
342 9
336 7 P336L,
344 12 A344S,
381 11 c.1140+1G>A, c.1141-3C>A,
322 13
1691 10
380 10
281 9 V281M,