SCN5A Variant M794R Detail

We estimate the penetrance of LQTS for SCN5A M794R around 11% and the Brugada syndrome penetrance around 10%. SCN5A M794R was found in a total of 0 carriers in 0 papers and/or in gnomAD: 0 had Brugada syndrome, 0 had LQTS. M794R is not present in gnomAD. M794R has been functionally characterized in 0 papers. This residue is located in a Non_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 (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 M794R around 11% (0/10) and the Brugada syndrome penetrance around 10% (1/10).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density BrS (%) Penetrance Density LQT3 (%)
NA NA NA 0.961 3 10
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 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.

M794R has 36 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 7 G797V,
810 9
784 15 F784L,
811 11 R811G, c.2435_2436+3delTGGTAinsCGCCT, R811H,
754 14
796 8
802 13
785 15 D785N,
808 12 R808C, R808P, R808H,
801 12 M801V, p.801_803delMSN/insS,
803 12
814 13 R814Q,
789 9 V789A, V789I,
807 6
753 14
760 15 p.F760SfsX5,
813 13 c.2436+12G>A, c.2437-5C>A,
757 12
788 10 I788V,
795 6
786 11
761 13
805 12 S805L,
792 6
799 10
787 10
794 0
798 7
804 11
791 5 L791F,
809 12
793 6 L793F,
806 10 V806M,
800 11 R800H, R800L, R800C,
790 6