SCN5A Variant c.486delC Detail

We estimate the penetrance of LQTS for SCN5A c.486delC around 3% and the Brugada syndrome penetrance around 45%. SCN5A c.486delC was found in a total of 1 carriers in 1 papers and/or in gnomAD: 1 had Brugada syndrome, 0 had LQTS. c.486delC is not present in gnomAD. c.486delC has been functionally characterized in 1 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 c.486delC around 3% (0/11) and the Brugada syndrome penetrance around 45% (4/11).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density BrS (%) Penetrance Density LQT3 (%)
NA NA NA None 57 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
20129283 2010 1 0 1 0
LITERATURE, COHORT, AND GNOMAD: - 1 0 0 1 -
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.

Functional Data

Peak and late/persistent current are relative to wildtype (100% being no different from wildtype). V0.5 act/inact are the voltages at which half of the maximal current is reached during an activation and inactivation protocol, each is in units of mV and relative to wildtype.
PubMed ID Year Cell Type Peak Current (%WT) V1/2 Act. (mV) V1/2 Inact. (mV) Late/Persistent Current (%WT)
20129283 2010

c.486delC has 37 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
147 11
164 5 F164L,
170 11 F170I,
171 13
143 11
137 12 I137V,
142 15
156 15 W156R, W156X,
158 10 K158T,
163 0 c.486delC,
169 10
222 13 R222X, R222L, R222Q,
157 10 T157I,
160 5 p.V160fs,
205 13 c.612-2A>G, Y205X,
166 5 A166T,
144 11
172 15
139 13 p.I137_C139dup,
148 14
165 6
204 12 A204T, c.611+1G>A, A204V, c.611+3_611+4dupAA,
162 6 Y162C, Y162H,
146 15 V146A, V146M,
208 11 E208K,
136 13 L136P,
168 9
141 13 I141N, I141V,
167 6
161 7 E161K, E161Q,
201 13
225 14 R225Q, R225W,
151 15
159 7 Y159C, Y159X,
207 14
145 15
140 9