SCN5A Variant S329I Detail

We estimate the penetrance of LQTS for SCN5A S329I around 11% and the Brugada syndrome penetrance around 22%. SCN5A S329I was found in a total of 0 carriers in 0 papers and/or in gnomAD: 0 had Brugada syndrome, 0 had LQTS. S329I is not present in gnomAD. S329I 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 S329I around 11% (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 0.675 27 12
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.

S329I has 43 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 7 c.998+1G>A, c.998+5G>A,
271 14 L271V,
1702 14
326 9
276 14 L276Q, L276P,
387 8
385 6 A385T,
330 4 S330F,
278 11 H278D, H278R,
388 9 I388S,
1698 14 A1698T,
334 8 c.999-424_1338+81del,
332 4 A332T,
327 6
384 8 S384T,
329 0
1692 14
386 6 G386E, G386R,
378 14
1699 14
331 6
379 15
272 13
341 10 C341Y,
274 14 G274C,
335 10 C335R, C335S,
325 12 L325R,
1690 15 c.5068_5070delGA, D1690N,
389 10 Y389H, Y389X,
1620 14 T1620K, T1620M,
390 14
275 11 N275K,
383 10
280 14 C280Y,
1614 14
382 9
1689 15 D1689N,
342 14
336 14 P336L,
381 11 c.1140+1G>A, c.1141-3C>A,
1691 11
380 14