SCN5A Variant T169A Detail

We estimate the penetrance of LQTS for SCN5A T169A around 4% and the Brugada syndrome penetrance around 17%. SCN5A T169A was found in a total of 0 carriers in 0 papers and/or in gnomAD: 0 had Brugada syndrome, 0 had LQTS. T169A is not present in gnomAD. T169A 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 T169A around 4% (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 0.955 16 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.

T169A has 46 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
198 9
124 14 A124D,
164 10 F164L,
209 14 N209S, N209T,
170 6 F170I,
171 7
137 11 I137V,
197 11
163 10 c.486delC,
196 15
169 0
177 12 L177P,
222 14 R222X, R222Q, R222L,
127 15
174 9 V174I,
133 13
160 14 p.V160fs,
205 8 c.612-2A>G, Y205X,
206 13
166 5 A166T,
144 15
172 5
199 12 S199T,
165 6
204 10 A204T, c.611+3_611+4dupAA, c.611+1G>A, A204V,
162 11 Y162C, Y162H,
203 13
208 11 E208K,
136 14 L136P,
168 6
175 10 K175N,
202 10 I202T,
194 14
141 14 I141N, I141V,
188 14
167 6
178 15 A178G,
128 14 c.381dupT,
161 13 E161K, E161Q,
201 7
225 12 R225W, R225Q,
176 11
207 14
173 7
200 11
140 12