SCN5A Variant F133I Detail

We estimate the penetrance of LQTS for SCN5A F133I around 4% and the Brugada syndrome penetrance around 33%. SCN5A F133I was found in a total of 0 carriers in 0 papers and/or in gnomAD: 0 had Brugada syndrome, 0 had LQTS. F133I is not present in gnomAD. F133I has been functionally characterized in 0 papers. This residue is located in a 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 (3 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 F133I around 4% (0/10) and the Brugada syndrome penetrance around 33% (3/10).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density BrS (%) Penetrance Density LQT3 (%)
NA NA NA 0.896 44 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 12 0 3 - -
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.

F133I has 42 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
231 14 c.692_693delCA,
198 15
124 10 A124D,
131 7
164 14 F164L,
130 6
170 8 F170I,
228 13 K228R,
138 9 M138I,
171 7
137 6 I137V,
142 14
197 13
129 8
169 13
177 13 L177P,
123 12 A123V, A123G,
127 6
125 10 V125L,
232 14 V232F, V232I,
174 8 V174I,
133 0
132 6 c.393-5C>A,
134 4 N134S,
166 13 A166T,
179 14 R179Q, R179X,
172 11
139 10 p.I137_C139dup,
126 11 K126E,
136 6 L136P,
168 11
175 9 K175N,
194 15
141 12 I141N, I141V,
135 8 M135V,
167 10
178 12 A178G,
128 6 c.381dupT,
225 13 R225W, R225Q,
176 14
173 12
140 10