SCN5A Variant T143N Detail

We estimate the penetrance of LQTS for SCN5A T143N around 4% and the Brugada syndrome penetrance around 15%. SCN5A T143N was found in a total of 0 carriers in 0 papers and/or in gnomAD: 0 had Brugada syndrome, 0 had LQTS. T143N is not present in gnomAD. T143N 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 T143N around 4% (0/10) and the Brugada syndrome penetrance around 15% (1/10).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density BrS (%) Penetrance Density LQT3 (%)
NA NA NA 0.894 12 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.

T143N has 39 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 15 I848F,
223 13 V223L,
149 10
147 7
164 7 F164L,
228 14 K228R,
138 9 M138I,
171 15
143 0
137 10 I137V,
142 5
229 12
163 11 c.486delC,
851 13 c.2552_2553dupGT, p.F851CfsX19, F851L, c.2550_2551dupGT,
222 13 R222Q, R222L, R222X,
150 10
232 14 V232F, V232I,
157 12 T157I,
160 9 p.V160fs,
134 15 N134S,
226 11 A226V, A226G,
166 14 A166T,
144 5
855 14
139 6 p.I137_C139dup,
148 9
165 13
146 5 V146M, V146A,
136 11 L136P,
168 11
141 6 I141V, I141N,
135 13 M135V,
167 11
161 11 E161Q, E161K,
225 11 R225Q, R225W,
151 12
159 13 Y159C, Y159X,
145 6
140 5