SCN5A Variant F888I Detail

We estimate the penetrance of LQTS for SCN5A F888I around 4% and the Brugada syndrome penetrance around 36%. SCN5A F888I was found in a total of 0 carriers in 0 papers and/or in gnomAD: 0 had Brugada syndrome, 0 had LQTS. F888I is not present in gnomAD. F888I 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 (3 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 F888I around 4% (0/10) and the Brugada syndrome penetrance around 36% (3/10).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density BrS (%) Penetrance Density LQT3 (%)
NA NA NA 0.947 49 1
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 12 0 3 - -
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.

F888I has 68 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 6 I891N, I891T,
880 12
888 0
848 11 I848F,
223 14 V223L,
856 12 V856L,
890 7 I890T,
919 13
896 11 C896S,
895 10 L895F,
1445 13 Y1445H,
894 10 I894M,
1455 13
1447 7
1444 11 L1444I,
149 12
1449 14 Y1449C, Y1449S,
1452 12
926 13
1429 14
1450 12
887 5
1451 8 V1451D, V1451L,
886 8 H886P, H886Q,
851 8 c.2550_2551dupGT, c.2552_2553dupGT, F851L, p.F851CfsX19,
897 14 G897R, G897E,
852 11
854 7 c.2559delT,
845 14 c.2533delG,
1422 13 M1422R,
857 11 G857D,
1418 15
902 13
882 14
892 6 F892I,
881 11
849 11
898 14
893 10 R893H, R893C,
922 12 V922I,
889 4
843 14 T843A,
1459 14 c.4376_4379delTCTT,
858 11 M858L,
918 15
855 10
1425 12
1454 12
1446 13
148 14
1448 9 I1448T, I1448L,
884 6
878 15 R878H, R878C, R878L,
1421 13
885 7
847 9
146 15 V146A, V146M,
846 10 L846R,
152 14 D152N,
853 10
879 11 W879R,
923 15
883 10
844 14 L844RfsX3,
850 6 V850M, c.2549_2550insTG,
145 14
861 15 p.F861WfsX90, c.2582_2583delTT,
931 15