SCN5A Variant c.611+1G>A Detail

We estimate the penetrance of LQTS for SCN5A c.611+1G>A around 8% and the Brugada syndrome penetrance around 64%. SCN5A c.611+1G>A was found in a total of 11 carriers in 6 papers and/or in gnomAD: 9 had Brugada syndrome, 1 had LQTS. c.611+1G>A is not present in gnomAD. c.611+1G>A has been functionally characterized in 6 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 (4 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.611+1G>A around 8% (1/21) and the Brugada syndrome penetrance around 64% (13/21).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density BrS (%) Penetrance Density LQT3 (%)
NA NA NA None 64 3
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
24606995 2014 1 1 0 0
26111534 2015 1 0 0 1 SND, AF
20129283 2010 1 0 1 0
29325976 2018 1 0 1 0
29709101 2018 9 0 8 0
30059973 2018 2 2 0 0
LITERATURE, COHORT, AND GNOMAD: - 11 1 1 9 -
VARIANT FEATURES ALONE: - 15 11 0 4 - -
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)
30059973 2018
24606995 2014
26111534 2015
20129283 2010
29325976 2018
29709101 2018

c.611+1G>A has 51 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
223 11 V223L,
859 13
198 11
147 14
164 10 F164L,
209 8 N209S, N209T,
195 14
171 13
158 12 K158T,
197 12
163 12 c.486delC,
216 12 S216L, S216X,
221 10
196 13
169 10
222 6 R222X, R222L, R222Q,
224 12 L224F,
160 13 p.V160fs,
226 15 A226V, A226G,
205 6 Y205X, c.612-2A>G,
206 5
166 10 A166T,
214 14
211 12
144 12
217 10
172 13
199 9 S199T,
148 13
165 7
210 11 I210T,
204 0 c.611+3_611+4dupAA, c.611+1G>A, A204T, A204V,
162 10 Y162H, Y162C,
203 5
208 6 E208K,
168 9
202 6 I202T,
141 14 I141N, I141V,
167 12
161 9 E161K, E161Q,
201 5
219 9 c.656_657insATTCA, R219H, R219C, p.R219HfsX11,
225 11 R225Q, R225W,
151 15
218 7
207 5
212 12 L212P, L212Q,
215 13 p.L215CfsX10,
200 7
140 14
220 11 T220I,