SCN5A Variant D785N Detail

We estimate the penetrance of LQTS for SCN5A D785N around 2% and the Brugada syndrome penetrance around 53%. SCN5A D785N was found in a total of 2 carriers in 1 papers and/or in gnomAD: 2 had Brugada syndrome, 0 had LQTS. D785N is not present in gnomAD. D785N has been functionally characterized in 2 papers. This residue is located in a 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 (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 D785N around 2% (0/12) and the Brugada syndrome penetrance around 53% (6/12).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density BrS (%) Penetrance Density LQT3 (%)
-4.95 0.961 -2.43 0.971 65 1
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
24581105 2014 2 0 2 0
LITERATURE, COHORT, AND GNOMAD: - 2 0 0 2 -
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)
24581105 2014
32533946 2020 HEK 39 11.8 -7.1

D785N has 57 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
723 10 I723V,
766 13
758 13 G758E,
811 14 R811G, R811H, c.2435_2436+3delTGGTAinsCGCCT,
821 13
769 15
773 14 P773S,
760 8 p.F760SfsX5,
776 8 p.Y776del,
780 8
765 11
812 14 L812Q,
759 12 I759V, c.2274delG, p.I759FfsX6,
792 11
764 6 M764R, M764K,
777 10 F777L,
791 11 L791F,
819 12
726 13
818 11
781 7 W781X,
720 11
788 5 I788V,
724 12 T724I,
782 6 N782T,
793 13 L793F,
820 10
762 11
810 13
727 11
767 9
770 15
756 14
814 9 R814Q,
816 11 F816Y, F816L,
722 14
813 9 c.2437-5C>A, c.2436+12G>A,
757 12
768 10
786 5
817 6 K817E,
761 10
779 10 Q779K, Q779X,
815 11
778 14
790 10
784 4 F784L,
763 10 E763K, E763D,
771 13 L771V,
785 0 D785N,
783 7 I783T,
730 14 N730K,
789 7 V789A, V789I,
714 13 V714D, V714A,
787 7
794 15