SCN5A Variant T157I Detail

We estimate the penetrance of LQTS for SCN5A T157I around 6% and the Brugada syndrome penetrance around 11%. SCN5A T157I was found in a total of 1 carriers in 0 papers and/or in gnomAD: 0 had Brugada syndrome, 0 had LQTS. T157I is present in 1 alleles in gnomAD. T157I 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 T157I around 6% (0/11) and the Brugada syndrome penetrance around 11% (1/11).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density BrS (%) Penetrance Density LQT3 (%)
-3.78 0.993 0.35 0.608 9 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: - 1 1 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.

T157I has 29 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
208 14 E208K,
154 9 P154L,
158 6 K158T,
156 6 W156X, W156R,
163 10 c.486delC,
166 15 A166T,
152 12 D152N,
161 7 E161Q, E161K,
219 13 c.656_657insATTCA, R219H, R219C, p.R219HfsX11,
144 11
151 8
146 12 V146A, V146M,
222 13 R222L, R222Q, R222X,
159 5 Y159C, Y159X,
153 10
155 6
149 12
147 7
207 15
150 9
164 10 F164L,
157 0 T157I,
148 12
160 5 p.V160fs,
165 13
145 14
140 15
162 9 Y162H, Y162C,
143 12