SCN5A Variant L921F Detail

We estimate the penetrance of LQTS for SCN5A L921F around 4% and the Brugada syndrome penetrance around 17%. SCN5A L921F was found in a total of 0 carriers in 0 papers and/or in gnomAD: 0 had Brugada syndrome, 0 had LQTS. L921F is not present in gnomAD. L921F has been functionally characterized in 0 papers. This residue is located in a Mild_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 (1 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 L921F around 4% (0/10) and the Brugada syndrome penetrance around 17% (1/10).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density BrS (%) Penetrance Density LQT3 (%)
NA NA NA 0.743 18 2
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 14 0 1 - -
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.

L921F has 59 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 11 I891N, I891T,
848 15 I848F,
223 15 V223L,
856 11 V856L,
890 14 I890T,
919 7
363 14
896 15 C896S,
895 12 L895F,
894 10 I894M,
247 11 V247L,
254 12
926 9
250 13
928 10 L928P,
925 6 I925F,
227 15 L227P,
366 12
246 14
897 13 G897R, G897E,
221 13
924 6 V924I,
927 11 N927S, N927K,
852 12
854 13 c.2559delT,
224 14 L224F,
857 12 G857D,
902 14
849 10
921 0
922 5 V922I,
362 15
860 13 p.L860fsx89,
920 5
900 14
930 13 c.2787+17_2787+18insACACACACACACACACACACACA, c.2788-6C>T,
918 5
855 15
917 6 L917R, L917V,
913 13
251 15
916 9
929 11
906 14
408 14
846 14 L846R,
903 12 p.M903CfsX29,
853 8
370 14 T370M,
923 7
915 11 C915R,
899 11
850 12 V850M, c.2549_2550insTG,
914 11
243 14
861 13 p.F861WfsX90, c.2582_2583delTT,
220 14 T220I,
907 14
931 14