SCN5A Variant I201M Detail

We estimate the penetrance of LQTS for SCN5A I201M around 4% and the Brugada syndrome penetrance around 23%. SCN5A I201M was found in a total of 0 carriers in 0 papers and/or in gnomAD: 0 had Brugada syndrome, 0 had LQTS. I201M is not present in gnomAD. I201M 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 I201M around 4% (0/10) and the Brugada syndrome penetrance around 23% (2/10).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density BrS (%) Penetrance Density LQT3 (%)
NA NA NA 0.767 28 1
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.

I201M 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
223 12 V223L,
198 6
193 14 W193R, W193X,
164 11 F164L,
209 12 N209S, N209T,
195 10
170 12 F170I,
228 12 K228R,
138 14 M138I,
227 14 L227P,
171 9
137 12 I137V,
197 7
163 13 c.486delC,
221 12
196 9
169 7
189 12
222 9 R222X, R222Q, R222L,
224 11 L224F,
174 13 V174I,
191 15
226 13 A226G, A226V,
205 7 c.612-2A>G, Y205X,
206 9
166 10 A166T,
144 13
217 14
172 8
185 14 A185T, A185V,
199 6 S199T,
165 7
204 5 A204T, c.611+3_611+4dupAA, c.611+1G>A, A204V,
162 13 Y162C, Y162H,
203 7
208 10 E208K,
192 14
168 6
175 11 K175N,
202 5 I202T,
194 11
141 12 I141N, I141V,
188 13
167 10
161 12 E161K, E161Q,
201 0
219 13 c.656_657insATTCA, R219H, p.R219HfsX11, R219C,
225 8 R225W, R225Q,
218 11
176 13
207 10
173 12
200 5
140 13
220 14 T220I,