SCN5A Variant A217G Detail

We estimate the penetrance of LQTS for SCN5A A217G around 7% and the Brugada syndrome penetrance around 17%. SCN5A A217G was found in a total of 0 carriers in 0 papers and/or in gnomAD: 0 had Brugada syndrome, 0 had LQTS. A217G is not present in gnomAD. A217G 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 A217G around 7% (0/10) and the Brugada syndrome penetrance around 17% (1/10).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density BrS (%) Penetrance Density LQT3 (%)
NA NA NA 0.852 17 5
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.

A217G has 44 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
223 11 V223L,
856 10 V856L,
862 13
859 8
209 13 N209S, N209T,
863 13
864 14
216 4 S216X, S216L,
221 5
196 15
852 14
854 15 c.2559delT,
222 9 R222Q, R222L, R222X,
224 11 L224F,
213 11
857 11 G857D,
205 14 Y205X, c.612-2A>G,
860 8 p.L860fsx89,
206 10
214 9
858 13 M858L,
211 12
217 0
918 14
855 12
913 14
199 12 S199T,
148 15
210 14 I210T,
204 10 c.611+1G>A, A204V, A204T, c.611+3_611+4dupAA,
910 15 S910L,
203 7
208 13 E208K,
202 12 I202T,
201 14
219 7 R219H, p.R219HfsX11, R219C, c.656_657insATTCA,
218 4
207 9
212 11 L212Q, L212P,
215 5 p.L215CfsX10,
914 11
200 11
861 12 p.F861WfsX90, c.2582_2583delTT,
220 4 T220I,