SCN5A Variant S172C Detail

We estimate the penetrance of LQTS for SCN5A S172C around 4% and the Brugada syndrome penetrance around 25%. SCN5A S172C was found in a total of 0 carriers in 0 papers and/or in gnomAD: 0 had Brugada syndrome, 0 had LQTS. S172C is not present in gnomAD. S172C 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 (2 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 S172C around 4% (0/10) and the Brugada syndrome penetrance around 25% (2/10).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density BrS (%) Penetrance Density LQT3 (%)
NA NA NA 0.85 31 0
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 13 0 2 - -
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.

S172C has 55 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
121 14 R121W, R121Q,
198 6
124 11 A124D,
164 14 F164L,
195 13
114 14
170 7 F170I,
184 13 H184R,
228 14 K228R,
138 15 M138I,
171 5
137 11 I137V,
197 8
129 14
163 15 c.486delC,
196 13
169 5
177 8 L177P,
189 12
123 15 A123V, A123G,
127 12
125 13 V125L,
174 6 V174I,
133 11
182 14 C182R, C182Y,
191 14
134 13 N134S,
205 11 c.612-2A>G, Y205X,
166 10 A166T,
179 11 R179X, R179Q,
172 0
185 11 A185V, A185T,
199 11 S199T,
165 10
180 11 G180V,
204 13 c.611+1G>A, c.611+3_611+4dupAA, A204T, A204V,
203 14
136 15 L136P,
168 8
175 5 K175N,
202 10 I202T,
194 10
141 14 I141N, I141V,
188 9
167 9
178 10 A178G,
128 10 c.381dupT,
201 8
225 12 R225Q, R225W,
181 12
176 6
173 5
200 11
140 14
187 14 T187I, T187S,