SCN5A Variant I787N Detail

We estimate the penetrance of LQTS for SCN5A I787N around 5% and the Brugada syndrome penetrance around 20%. SCN5A I787N was found in a total of 0 carriers in 0 papers and/or in gnomAD: 0 had Brugada syndrome, 0 had LQTS. I787N is not present in gnomAD. I787N has been functionally characterized in 0 papers. This residue is located in a Mild_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 I787N around 5% (0/10) and the Brugada syndrome penetrance around 20% (1/10).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density BrS (%) Penetrance Density LQT3 (%)
NA NA NA 0.94 20 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
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.

I787N has 41 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
811 13 c.2435_2436+3delTGGTAinsCGCCT, R811H, R811G,
773 15 P773S,
760 12 p.F760SfsX5,
780 10
776 11 p.Y776del,
765 14
812 13 L812Q,
792 9
764 10 M764R, M764K,
777 10 F777L,
791 6 L791F,
806 15 V806M,
781 11 W781X,
788 5 I788V,
782 10 N782T,
793 11 L793F,
820 15
762 15
810 9
767 14
814 10 R814Q,
807 12
816 12 F816Y, F816L,
813 8 c.2437-5C>A, c.2436+12G>A,
757 13
768 13
786 4
817 11 K817E,
761 12
779 13 Q779K, Q779X,
809 13
815 13
790 5
784 6 F784L,
796 15
785 7 D785N,
783 6 I783T,
789 7 V789A, V789I,
795 13
787 0
794 10