SCN5A Variant D197G Detail

We estimate the penetrance of LQTS for SCN5A D197G around 5% and the Brugada syndrome penetrance around 17%. SCN5A D197G was found in a total of 0 carriers in 0 papers and/or in gnomAD: 0 had Brugada syndrome, 0 had LQTS. D197G is not present in gnomAD. D197G 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 D197G around 5% (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 0.983 15 2
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.

D197G has 60 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 12 V223L,
231 12 c.692_693delCA,
198 5
193 8 W193R, W193X,
164 14 F164L,
195 8
184 15 H184R,
170 13 F170I,
228 7 K228R,
138 11 M138I,
227 10 L227P,
171 7
137 10 I137V,
142 15
197 0
229 12
221 13
196 5
190 14 R190L, R190Q, R190G, R190W,
169 11
189 10
222 13 R222X, R222L, R222Q,
224 10 L224F,
232 15 V232I, V232F,
174 12 V174I,
133 13
191 9
134 12 N134S,
226 10 A226G, A226V,
205 14 c.612-2A>G, Y205X,
166 14 A166T,
179 14 R179Q, R179X,
144 14
172 8
230 13 I230V, I230T, I230M,
185 12 A185T, A185V,
199 7 S199T,
165 12
180 15 G180V,
204 12 A204T, c.611+1G>A, c.611+3_611+4dupAA, A204V,
203 11
192 9
136 15 L136P,
168 8
175 8 K175N,
202 10 I202T,
194 5
141 10 I141N, I141V,
188 9
167 12
178 14 A178G,
128 12 c.381dupT,
201 7
225 6 R225W, R225Q,
176 11
186 15
173 13
200 7
140 13
187 13 T187S, T187I,