SCN5A Variant M881I Detail

We estimate the penetrance of LQTS for SCN5A M881I around 4% and the Brugada syndrome penetrance around 54%. SCN5A M881I was found in a total of 0 carriers in 0 papers and/or in gnomAD: 0 had Brugada syndrome, 0 had LQTS. M881I is not present in gnomAD. M881I 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 (5 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 M881I around 4% (0/10) and the Brugada syndrome penetrance around 54% (5/10).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density BrS (%) Penetrance Density LQT3 (%)
NA NA NA 0.972 81 0
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 10 0 5 - -
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.

M881I has 69 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
891 9 I891T, I891N,
880 6
888 11
223 15 V223L,
856 9 V856L,
890 7 I890T,
901 13 S901L, E901K,
919 10
862 5
867 13 E867K, E867Q, E867X,
859 9
894 12 I894M,
1444 14 L1444I,
1440 15 W1440X,
149 14
863 10
904 15 W904X,
887 5
864 9
886 7 H886P, H886Q,
216 15 S216L, S216X,
851 13 c.2552_2553dupGT, F851L, c.2550_2551dupGT, p.F851CfsX19,
909 10
852 13
854 8 c.2559delT,
876 10
857 5 G857D,
868 13 c.2602delC, L868X,
902 9
882 6
892 14 F892I,
881 0
893 12 R893H, R893C,
922 13 V922I,
860 9 p.L860fsx89,
911 14 G911E,
889 10
858 6 M858L,
918 11
855 9
865 6
913 14
916 15
148 14
884 9
906 8
866 11 S866P, S866L,
910 10 S910L,
878 13 R878L, R878H, R878C,
885 11
903 12 p.M903CfsX29,
1441 15 E1441Q,
152 12 D152N,
853 11
219 14 R219H, c.656_657insATTCA, R219C, p.R219HfsX11,
877 9
151 14
879 10 W879R,
869 14 R869S,
883 7
905 10
915 10 C915R,
875 13
850 13 c.2549_2550insTG, V850M,
908 13
914 12
861 6 c.2582_2583delTT, p.F861WfsX90,
220 13 T220I,
907 13