SCN5A Variant L818R Detail

We estimate the penetrance of LQTS for SCN5A L818R around 12% and the Brugada syndrome penetrance around 34%. SCN5A L818R was found in a total of 0 carriers in 0 papers and/or in gnomAD: 0 had Brugada syndrome, 0 had LQTS. L818R is not present in gnomAD. L818R has been functionally characterized in 0 papers. This residue is located in a 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 (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 L818R around 12% (0/10) and the Brugada syndrome penetrance around 34% (3/10).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density BrS (%) Penetrance Density LQT3 (%)
NA NA NA 0.991 46 12
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.

L818R has 54 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
719 15
723 10 I723V,
811 15 c.2435_2436+3delTGGTAinsCGCCT, R811H, R811G,
733 15 F733L,
821 5
1340 11 V1340I,
1339 11 p.L1339del, L1339F,
760 12 p.F760SfsX5,
780 15
721 12
812 11 L812Q,
1350 14 I1350L, I1350T,
1344 11 F1344S, F1344L,
731 9 T731I,
819 5
826 10 N826D,
726 11
818 0
825 8
781 10 W781X,
720 11
822 6 W822C, W822X,
788 12 I788V,
1346 11 L1346I, L1346P,
724 7 T724I,
782 15 N782T,
1341 14
728 8 V728I,
820 8
823 10 P823T,
727 6
735 14 A735V, A735E, A735T,
732 12
734 12 M734V, c.2201dupT,
756 14
827 14
814 10 R814Q,
816 7 F816Y, F816L,
722 13
813 11 c.2437-5C>A, c.2436+12G>A,
817 5 K817E,
815 6
1343 8
1342 12
725 11
784 11 F784L,
785 11 D785N,
730 11 N730K,
1347 11
729 12 p.L729del,
1336 15
824 11
829 12
828 13 L828V,