SCN5A Variant T165N Detail

We estimate the penetrance of LQTS for SCN5A T165N around 4% and the Brugada syndrome penetrance around 22%. SCN5A T165N was found in a total of 0 carriers in 0 papers and/or in gnomAD: 0 had Brugada syndrome, 0 had LQTS. T165N is not present in gnomAD. T165N 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 T165N around 4% (0/10) and the Brugada syndrome penetrance around 22% (2/10).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density BrS (%) Penetrance Density LQT3 (%)
NA NA NA 0.923 25 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.

T165N has 49 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 14 V223L,
198 12
147 12
164 6 F164L,
209 12 N209S, N209T,
170 10 F170I,
138 15 M138I,
171 10
143 13
137 12 I137V,
158 11 K158T,
197 12
163 6 c.486delC,
169 6
222 9 R222X, R222L, R222Q,
174 14 V174I,
157 13 T157I,
160 9 p.V160fs,
205 8 Y205X, c.612-2A>G,
206 11
166 4 A166T,
144 10
172 10
199 13 S199T,
139 15 p.I137_C139dup,
148 14
165 0
210 14 I210T,
204 7 A204T, c.611+3_611+4dupAA, A204V, c.611+1G>A,
162 6 Y162C, Y162H,
203 12
208 7 E208K,
136 15 L136P,
168 5
202 10 I202T,
175 14 K175N,
141 12 I141V, I141N,
167 6
161 7 E161K, E161Q,
201 7
219 13 p.R219HfsX11, R219H, c.656_657insATTCA, R219C,
225 11 R225Q, R225W,
218 13
159 11 Y159X, Y159C,
207 10
173 13
200 10
145 15
140 10