SCN5A Variant L825M Detail

We estimate the penetrance of LQTS for SCN5A L825M around 13% and the Brugada syndrome penetrance around 16%. SCN5A L825M was found in a total of 0 carriers in 0 papers and/or in gnomAD: 0 had Brugada syndrome, 0 had LQTS. L825M is not present in gnomAD. L825M 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 (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 L825M around 13% (0/10) and the Brugada syndrome penetrance around 16% (1/10).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density BrS (%) Penetrance Density LQT3 (%)
NA NA NA 0.726 16 14
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.

L825M 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
821 8
1340 7 V1340I,
1339 8 L1339F, p.L1339del,
1461 13 T1461S,
1333 14
1344 9 F1344L, F1344S,
731 15 T731I,
819 4
826 5 N826D,
818 8
825 0
781 11 W781X,
1464 13 c.4389_4396delCCTCTTTA, L1464P,
822 6 W822C, W822X,
944 14
830 10
1346 13 L1346P, L1346I,
833 13 G833R,
724 13 T724I,
1341 11
831 10
728 15 V728I,
820 9
823 6 P823T,
727 14
942 13
1456 14
834 14 N834D,
827 7
1460 13 F1460L,
816 9 F816L, F816Y,
813 14 c.2436+12G>A, c.2437-5C>A,
1338 12 L1338V,
817 11 K817E,
815 10
1343 8
1345 14 W1345C,
1337 10
1342 12
784 14 F784L,
1347 12
1336 10
824 4
829 6
1335 14 M1335R,
832 10
828 5 L828V,