SCN5A Variant I141M Detail

We estimate the penetrance of LQTS for SCN5A I141M around 3% and the Brugada syndrome penetrance around 12%. SCN5A I141M was found in a total of 0 carriers in 0 papers and/or in gnomAD: 0 had Brugada syndrome, 0 had LQTS. I141M is not present in gnomAD. I141M has been functionally characterized in 0 papers. This residue is located in a Non_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 I141M around 3% (0/10) and the Brugada syndrome penetrance around 12% (1/10).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density BrS (%) Penetrance Density LQT3 (%)
NA NA NA 0.846 7 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 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.

I141M 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
848 11 I848F,
223 10 V223L,
231 11 c.692_693delCA,
198 14
149 13
147 11
193 14 W193R, W193X,
164 8 F164L,
170 15 F170I,
228 7 K228R,
138 5 M138I,
227 10 L227P,
171 11
143 6
137 6 I137V,
142 5
197 10
229 7
163 13 c.486delC,
851 11 p.F851CfsX19, c.2550_2551dupGT, c.2552_2553dupGT, F851L,
196 12
169 14
852 12
222 11 R222X, R222L, R222Q,
224 11 L224F,
150 15
232 11 V232F, V232I,
133 12
132 14 c.393-5C>A,
160 13 p.V160fs,
134 11 N134S,
226 6 A226G, A226V,
166 13 A166T,
144 6
855 14
172 14
230 11 I230M, I230V, I230T,
199 15 S199T,
139 6 p.I137_C139dup,
148 10
165 12
204 14 A204T, c.611+3_611+4dupAA, A204V, c.611+1G>A,
146 10 V146M, V146A,
847 15
136 10 L136P,
168 8
175 14 K175N,
233 14
194 15
141 0 I141V, I141N,
135 11 M135V,
167 10
161 13 E161K, E161Q,
201 12
225 5 R225Q, R225W,
151 15
844 15 L844RfsX3,
200 11
140 5
145 6