SCN5A Variant L828V Detail

We estimate the penetrance of LQTS for SCN5A L828V around 66% and the Brugada syndrome penetrance around 7%. SCN5A L828V was found in a total of 1 carriers in 1 papers and/or in gnomAD: 0 had Brugada syndrome, 1 had LQTS. L828V is not present in gnomAD. L828V has been functionally characterized in 1 papers. This residue is located in a Non_Hotspot region for Brugada syndrome and a Hotspot region for LQTS. In silico predictions, functional data (if available), and location in structure are equivalent to phenotyping 10 individuals for Brugada syndrome (0 diagnosed with Brugada syndrome) and 5 individuals for LQTS (2 with LQTS). These data combined with observations of carriers lead us to estimate the LQTS penetrance for SCN5A L828V around 66% (3/11) and the Brugada syndrome penetrance around 7% (0/11).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density BrS (%) Penetrance Density LQT3 (%)
-2.97 0.948 1.51 0.904 3 80
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
23631430 2013 1 1 0 0
LITERATURE, COHORT, AND GNOMAD: - 1 0 1 0 -
VARIANT FEATURES ALONE: - 15 13 2 0 - -
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.

Functional Data

Peak and late/persistent current are relative to wildtype (100% being no different from wildtype). V0.5 act/inact are the voltages at which half of the maximal current is reached during an activation and inactivation protocol, each is in units of mV and relative to wildtype.
PubMed ID Year Cell Type Peak Current (%WT) V1/2 Act. (mV) V1/2 Inact. (mV) Late/Persistent Current (%WT)
23631430 2013

L828V has 55 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
939 14 L939F,
937 14
839 13 L839P,
821 13
943 13 S943N,
1340 7 V1340I,
1457 13
1339 10 p.L1339del, L1339F,
1461 10 T1461S,
1333 13
1344 9 F1344S, F1344L,
819 9
836 13 V836M,
826 7 N826D,
818 13
825 5
934 14
781 14 W781X,
1464 9 c.4389_4396delCCTCTTTA, L1464P,
822 11 W822C, W822X,
944 11
830 8
833 9 G833R,
940 14 S940N,
1341 10
1334 14 I1334V,
1468 13 V1468A, V1468F,
831 6
1462 15
820 13
938 11
823 10 P823T,
942 8
1456 12
834 10 N834D,
827 5
1460 9 F1460L,
816 11 F816Y, F816L,
1338 13 L1338V,
815 14
1343 11
1345 14 W1345C,
941 10 S941F, S941N,
1337 9
1342 14
1465 13 p.F1465_L1480dup,
1467 13
1347 14
1336 10
824 7
829 4
832 6
835 10 S835L, S835A,
828 0 L828V,
1463 14 N1463Y,