SCN5A Variant N730K Detail

We estimate the penetrance of LQTS for SCN5A N730K around 18% and the Brugada syndrome penetrance around 18%. SCN5A N730K was found in a total of 1 carriers in 0 papers and/or in gnomAD: 0 had Brugada syndrome, 0 had LQTS. N730K is present in 1 alleles in gnomAD. N730K has been functionally characterized in 0 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 (1 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 N730K around 18% (1/11) and the Brugada syndrome penetrance around 18% (1/11).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density BrS (%) Penetrance Density LQT3 (%)
-5.7 0.049 -4.67 0.732 23 29
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: - 1 1 0 0 -
VARIANT FEATURES ALONE: - 15 13 1 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.

N730K has 61 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
723 11 I723V,
758 12 G758E,
811 8 R811G, R811H, c.2435_2436+3delTGGTAinsCGCCT,
733 5 F733L,
808 12 R808C, R808P, R808H,
745 15
821 14
1351 15 M1351V, M1351R,
760 9 p.F760SfsX5,
812 10 L812Q,
1350 11 I1350T, I1350L,
759 10 I759V, p.I759FfsX6, c.2274delG,
792 12
755 10
791 15 L791F,
731 5 T731I,
754 11
726 7
818 11
1353 14 V1353M,
737 11
750 12 Q750R,
1349 14
749 9
788 11 I788V,
1346 13 L1346I, L1346P,
724 10 T724I,
728 7 V728I,
810 14
727 6
735 9 A735T, A735E, A735V,
732 7
734 5 c.2201dupT, M734V,
756 6
814 6 R814Q,
816 13 F816L, F816Y,
722 13
813 12 c.2436+12G>A, c.2437-5C>A,
757 9
1354 13
817 11 K817E,
761 14
752 7 G752R,
1405 15 V1405M, V1405L,
809 13
815 9
1343 14
725 11
784 15 F784L,
763 14 E763K, E763D,
751 11 V751F, V751I,
796 14
736 11 L736P,
785 14 D785N,
730 0 N730K,
789 13 V789A, V789I,
753 7
1347 13
729 6 p.L729del,
795 13
748 11 M748I,