SCN5A Variant L771V Detail

We estimate the penetrance of LQTS for SCN5A L771V around 52% and the Brugada syndrome penetrance around 16%. SCN5A L771V was found in a total of 1 carriers in 1 papers and/or in gnomAD: 0 had Brugada syndrome, 1 had LQTS. L771V is not present in gnomAD. L771V has been functionally characterized in 1 papers. This residue is located in a Mild_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 (1 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 L771V around 52% (3/11) and the Brugada syndrome penetrance around 16% (1/11).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density BrS (%) Penetrance Density LQT3 (%)
-1.63 0.978 -2.31 0.779 18 62
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
26940925 2016 1 1 0 0
LITERATURE, COHORT, AND GNOMAD: - 1 0 1 0 -
VARIANT FEATURES ALONE: - 15 12 2 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.

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)
26940925 2016

L771V has 33 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 13
710 9
766 10
715 10 M715I, M715T,
713 11
712 11
762 13
774 10 p.Y774TfsX28, c.2320delT, Y774D, Y774C,
763 12 E763D, E763K,
778 10
767 6
772 5 D772N,
770 4
781 14 W781X,
775 7
771 0 L771V,
720 13
785 13 D785N,
783 13 I783T,
769 7
773 7 P773S,
714 7 V714D, V714A,
780 13
776 6 p.Y776del,
768 6
765 10
786 13
711 7
779 10 Q779X, Q779K,
764 10 M764R, M764K,
777 9 F777L,
782 9 N782T,
716 13