SCN5A Variant L796Q Detail

We estimate the penetrance of LQTS for SCN5A L796Q around 26% and the Brugada syndrome penetrance around 10%. SCN5A L796Q was found in a total of 0 carriers in 0 papers and/or in gnomAD: 0 had Brugada syndrome, 0 had LQTS. L796Q is not present in gnomAD. L796Q 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 (0 diagnosed with Brugada syndrome) and 5 individuals for LQTS (1 with LQTS). These data combined with observations of carriers lead us to estimate the LQTS penetrance for SCN5A L796Q around 26% (1/10) and the Brugada syndrome penetrance around 10% (0/10).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density BrS (%) Penetrance Density LQT3 (%)
NA NA NA 0.968 3 33
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 1 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.

L796Q 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
758 11 G758E,
811 9 c.2435_2436+3delTGGTAinsCGCCT, R811G, R811H,
808 10 R808C, R808P, R808H,
760 13 p.F760SfsX5,
759 14 p.I759FfsX6, c.2274delG, I759V,
792 6
755 12
791 10 L791F,
806 13 V806M,
800 5 R800L, R800H, R800C,
754 7
797 5 G797V,
801 10 M801V, p.801_803delMSN/insS,
750 9 Q750R,
749 13
788 12 I788V,
805 12 S805L,
798 7
793 6 L793F,
747 15 E747A,
810 12
734 15 M734V, c.2201dupT,
756 13
803 12
814 12 R814Q,
807 9
813 15 c.2436+12G>A, c.2437-5C>A,
757 8
761 12
752 11 G752R,
809 13
790 11
751 12 V751I, V751F,
796 0
802 11
730 14 N730K,
789 10 V789I, V789A,
753 9
795 4
799 6
787 15
794 8
804 13