SCN5A Variant G758E Detail

We estimate the penetrance of LQTS for SCN5A G758E around 9% and the Brugada syndrome penetrance around 50%. SCN5A G758E was found in a total of 1 carriers in 1 papers and/or in gnomAD: 1 had Brugada syndrome, 0 had LQTS. G758E is not present in gnomAD. G758E has been functionally characterized in 1 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 (4 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 G758E around 9% (0/11) and the Brugada syndrome penetrance around 50% (5/11).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density BrS (%) Penetrance Density LQT3 (%)
-6.43 0.521 -3.3 0.947 63 13
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
20129283 2010 1 0 1 0
LITERATURE, COHORT, AND GNOMAD: - 1 0 0 1 -
VARIANT FEATURES ALONE: - 15 11 0 4 - -
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)
20129283 2010

G758E has 43 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 14
723 11 I723V,
766 11
758 0 G758E,
811 13 c.2435_2436+3delTGGTAinsCGCCT, R811H, R811G,
733 14 F733L,
760 6 p.F760SfsX5,
765 10
759 4 I759V, c.2274delG, p.I759FfsX6,
792 9
764 10 M764K, M764R,
755 6
791 14 L791F,
800 14 R800H, R800C, R800L,
754 7
726 10
797 15 G797V,
750 13 Q750R,
788 11 I788V,
793 9 L793F,
762 6
727 13
767 13
756 7
814 11 R814Q,
722 13
757 4
768 14
786 13
817 15 K817E,
761 4
752 10 G752R,
790 13
763 8 E763D, E763K,
751 11 V751I, V751F,
796 11
785 13 D785N,
730 12 N730K,
789 9 V789I, V789A,
753 9
729 14 p.L729del,
795 13
794 14