SCN5A Variant F188I Detail

We estimate the penetrance of LQTS for SCN5A F188I around 5% and the Brugada syndrome penetrance around 22%. SCN5A F188I was found in a total of 0 carriers in 0 papers and/or in gnomAD: 0 had Brugada syndrome, 0 had LQTS. F188I is not present in gnomAD. F188I 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 F188I around 5% (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 0.983 24 2
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.

F188I has 44 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
121 14 R121W, R121Q,
198 6
124 14 A124D,
193 11 W193X, W193R,
195 10
114 12
170 15 F170I,
184 6 H184R,
228 14 K228R,
183 10
171 11
197 9
113 12 V113A, V113I,
129 15
196 11
190 9 R190W, R190L, R190Q, R190G,
169 14
177 11 L177P,
189 6
125 13 V125L,
174 11 V174I,
182 10 C182Y, C182R,
191 7
179 8 R179Q, R179X,
172 9
185 5 A185T, A185V,
199 11 S199T,
112 14 Y112C,
180 7 G180V,
192 10
175 7 K175N,
202 13 I202T,
194 5
188 0
178 9 A178G,
128 12 c.381dupT,
201 13
225 14 R225Q, R225W,
181 11
176 7
186 8
173 11
200 14
187 5 T187I, T187S,