SCN5A Variant F170I Detail

We estimate the penetrance of LQTS for SCN5A F170I around 7% and the Brugada syndrome penetrance around 11%. SCN5A F170I was found in a total of 1 carriers in 0 papers and/or in gnomAD: 0 had Brugada syndrome, 0 had LQTS. F170I is present in 1 alleles in gnomAD. F170I has been functionally characterized in 0 papers. This residue is located in a Non_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 F170I around 7% (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 (%)
-5.78 0.993 2.47 0.948 7 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.

F170I has 43 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 12
124 10 A124D,
164 12 F164L,
130 14
170 0 F170I,
138 15 M138I,
171 6
137 10 I137V,
197 13
129 14
163 11 c.486delC,
169 6
177 10 L177P,
123 12 A123G, A123V,
127 9
125 13 V125L,
174 6 V174I,
133 8
132 14 c.393-5C>A,
134 12 N134S,
205 14 c.612-2A>G, Y205X,
166 7 A166T,
179 15 R179Q, R179X,
172 7
139 15 p.I137_C139dup,
165 10
180 15 G180V,
120 13
126 14 K126E,
136 11 L136P,
168 9
175 9 K175N,
141 15 I141V, I141N,
188 15
167 6
178 12 A178G,
128 10 c.381dupT,
201 12
225 14 R225Q, R225W,
176 11
173 6
140 12