SCN5A Variant S940N Detail

We estimate the penetrance of LQTS for SCN5A S940N around 19% and the Brugada syndrome penetrance around 4%. SCN5A S940N was found in a total of 1 carriers in 0 papers and/or in gnomAD: 0 had Brugada syndrome, 0 had LQTS. S940N is present in 1 alleles in gnomAD. S940N has been functionally characterized in 0 papers. This residue is located in a Non_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 (0 diagnosed with Brugada syndrome) and 5 individuals for LQTS (1 with LQTS). These data combined with observations of carriers lead us to estimate the LQTS penetrance for SCN5A S940N around 19% (1/11) and the Brugada syndrome penetrance around 4% (0/11).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density BrS (%) Penetrance Density LQT3 (%)
-1.33 0.997 1.9 0.648 2 27
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: - 1 1 0 0 -
VARIANT FEATURES ALONE: - 15 14 1 0 - -
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.

S940N has 58 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
414 13 M414V,
939 5 L939F,
937 6
1773 14
839 11 L839P,
842 13
943 6 S943N,
418 13 E418K,
409 13 L409P, L409V,
836 14 V836M,
417 7
934 10
933 11
1471 10
935 10 L935P,
412 12 V412D,
1470 11
1464 12 c.4389_4396delCCTCTTTA, L1464P,
1466 13 c.4396_4397insG,
1776 14
944 10
830 14
833 13 G833R,
415 12 A415T,
940 0 S940N,
1468 13 V1468A, V1468F,
831 10
420 7
938 7
1474 14
840 14
942 7
419 12 Q419X,
423 13
834 11 N834D,
1772 14 L1772V,
827 15
1460 13 F1460L,
837 13
239 13 I239V, I239V ,
410 14 A410V,
242 13 A242D,
416 7 Y416C,
413 9 A413E, A413T,
841 14 N841K, p.N841TfsX2,
941 4 S941N, S941F,
936 6
238 11
838 10
422 14
1467 10
421 10
1469 15 I1469V,
932 14
832 12
835 10 S835L, S835A,
828 14 L828V,
1463 14 N1463Y,