SCN5A Variant Q859K Detail

We estimate the penetrance of LQTS for SCN5A Q859K around 13% and the Brugada syndrome penetrance around 31%. SCN5A Q859K was found in a total of 0 carriers in 0 papers and/or in gnomAD: 0 had Brugada syndrome, 0 had LQTS. Q859K is not present in gnomAD. Q859K 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 (3 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 Q859K around 13% (0/10) and the Brugada syndrome penetrance around 31% (3/10).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density BrS (%) Penetrance Density LQT3 (%)
NA NA NA 0.96 41 13
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 12 0 3 - -
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.

Q859K has 62 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
891 14 I891N, I891T,
880 14
154 14 P154L,
223 9 V223L,
856 6 V856L,
890 14 I890T,
919 15
862 7
867 13 E867X, E867K, E867Q,
859 0
149 12
147 13
863 8
887 11
156 12 W156X, W156R,
864 10
886 15 H886P, H886Q,
216 7 S216X, S216L,
851 13 c.2550_2551dupGT, c.2552_2553dupGT, F851L, p.F851CfsX19,
221 9
909 15
852 12
854 10 c.2559delT,
222 9 R222L, R222Q, R222X,
224 12 L224F,
213 14
857 6 G857D,
150 15
882 11
881 9
860 5 p.L860fsx89,
214 14
858 5 M858L,
144 14
217 8
918 13
855 7
865 12
913 15
148 10
884 12
906 14
866 13 S866L, S866P,
204 13 c.611+1G>A, c.611+3_611+4dupAA, A204T, A204V,
910 13 S910L,
203 13
152 12 D152N,
853 13
161 14 E161Q, E161K,
219 5 R219C, c.656_657insATTCA, p.R219HfsX11, R219H,
151 9
218 10
883 12
207 12
915 13 C915R,
212 13 L212P, L212Q,
215 11 p.L215CfsX10,
914 12
200 14
145 14
861 8 p.F861WfsX90, c.2582_2583delTT,
220 5 T220I,