SCN5A Variant R800L Detail

We estimate the penetrance of LQTS for SCN5A R800L around 28% and the Brugada syndrome penetrance around 8%. SCN5A R800L was found in a total of 3 carriers in 1 papers and/or in gnomAD: 0 had Brugada syndrome, 2 had LQTS. R800L is present in 1 alleles in gnomAD. R800L has been functionally characterized in 3 papers. This residue is located in a Non_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 R800L around 28% (2/13) and the Brugada syndrome penetrance around 8% (1/13).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density BrS (%) Penetrance Density LQT3 (%)
-3.84 0.003 -0.34 0.65 1 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
23376825 2013 2 2 0 0
LITERATURE, COHORT, AND GNOMAD: - 3 1 2 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.

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)
23376825 2013 HEK 108 -1 2 238
25904541 2015 HEK 63 -1 2 126
28412158 2017

R800L has 27 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
758 14 G758E,
797 4 G797V,
747 14 E747A,
811 14 c.2435_2436+3delTGGTAinsCGCCT, R811G, R811H,
751 13 V751I, V751F,
796 5
802 9
808 13 R808C, R808P, R808H,
801 6 M801V, p.801_803delMSN/insS,
803 11
750 10 Q750R,
807 13
753 12
757 12
795 8
805 14 S805L,
792 11
799 5
794 11
752 15 G752R,
798 7
804 14
755 14
791 14 L791F,
793 10 L793F,
800 0 R800L, R800C, R800H,
754 10