SCN5A Variant N864I Detail

We estimate the penetrance of LQTS for SCN5A N864I around 10% and the Brugada syndrome penetrance around 26%. SCN5A N864I was found in a total of 0 carriers in 0 papers and/or in gnomAD: 0 had Brugada syndrome, 0 had LQTS. N864I is not present in gnomAD. N864I 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 N864I around 10% (0/10) and the Brugada syndrome penetrance around 26% (2/10).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density BrS (%) Penetrance Density LQT3 (%)
NA NA NA 0.72 33 10
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.

N864I has 47 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
880 11
856 13 V856L,
890 15 I890T,
919 15
870 12
862 5
867 5 E867K, E867Q, E867X,
859 10
863 4
887 14
864 0
886 15 H886P, H886Q,
216 12 S216L, S216X,
871 12
909 6
876 11
857 10 G857D,
868 7 c.2602delC, L868X,
902 14
882 10
881 9
860 9 p.L860fsx89,
911 9 G911E,
858 11 M858L,
217 14
918 14
865 5
913 11
912 13 Q912R,
906 8
866 6 S866L, S866P,
874 14 G874D,
910 6 S910L,
903 14 p.M903CfsX29,
219 14 R219H, c.656_657insATTCA, R219C, p.R219HfsX11,
877 12
869 9 R869S,
883 14
905 11
915 11 C915R,
875 12
215 14 p.L215CfsX10,
908 10
914 11
861 7 c.2582_2583delTT, p.F861WfsX90,
220 14 T220I,
907 12