SCN5A Variant N328H Detail

We estimate the penetrance of LQTS for SCN5A N328H around 11% and the Brugada syndrome penetrance around 29%. SCN5A N328H was found in a total of 0 carriers in 0 papers and/or in gnomAD: 0 had Brugada syndrome, 0 had LQTS. N328H is not present in gnomAD. N328H 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 N328H around 11% (0/10) and the Brugada syndrome penetrance around 29% (2/10).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density BrS (%) Penetrance Density LQT3 (%)
NA NA NA 0.769 39 11
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.

N328H 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 0
333 8 c.998+5G>A, c.998+1G>A,
277 15
271 15 L271V,
326 8
276 13 L276Q, L276P,
387 12
279 13
385 7 A385T,
338 14
330 8 S330F,
278 8 H278R, H278D,
388 12 I388S,
334 7 c.999-424_1338+81del,
332 7 A332T,
343 12
327 4
339 14
384 7 S384T,
329 4
386 9 G386E, G386R,
340 11 R340W, R340Q,
331 10
272 14
341 6 C341Y,
274 13 G274C,
335 8 C335S, C335R,
325 11 L325R,
324 14
389 12 Y389H, Y389X,
275 10 N275K,
383 11
280 11 C280Y,
1614 14
382 12
337 15
342 10
336 12 P336L,
344 15 A344S,
381 12 c.1141-3C>A, c.1140+1G>A,
1691 13
380 15
281 13 V281M,