SCN5A Variant R222L Detail

We estimate the penetrance of LQTS for SCN5A R222L around 17% and the Brugada syndrome penetrance around 23%. SCN5A R222L was found in a total of 1 carriers in 0 papers and/or in gnomAD: 0 had Brugada syndrome, 0 had LQTS. R222L is present in 1 alleles in gnomAD. R222L has been functionally characterized in 0 papers. This residue is located in a Hotspot region for Brugada syndrome and a Mild_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 (1 with LQTS). These data combined with observations of carriers lead us to estimate the LQTS penetrance for SCN5A R222L around 17% (1/11) and the Brugada syndrome penetrance around 23% (2/11).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density BrS (%) Penetrance Density LQT3 (%)
-6.83 0.336 -6.53 0.966 28 30
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 12 1 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.

R222L has 70 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 6 V223L,
856 10 V856L,
859 9
198 14
149 13
147 10
164 9 F164L,
209 14 N209S, N209T,
195 15
228 14 K228R,
227 13 L227P,
171 15
143 13
137 15 I137V,
142 14
156 13 W156X, W156R,
158 12 K158T,
197 13
229 15
163 13 c.486delC,
216 10 S216L, S216X,
851 12 F851L, c.2552_2553dupGT, c.2550_2551dupGT, p.F851CfsX19,
221 8
196 12
169 14
852 11
854 13 c.2559delT,
222 0 R222X, R222Q, R222L,
224 8 L224F,
857 13 G857D,
150 14
157 13 T157I,
160 12 p.V160fs,
226 10 A226G, A226V,
205 12 c.612-2A>G, Y205X,
860 13 p.L860fsx89,
206 10
166 13 A166T,
858 12 M858L,
144 8
217 9
855 9
199 11 S199T,
148 7
165 9
884 15
210 15 I210T,
204 6 A204T, c.611+3_611+4dupAA, c.611+1G>A, A204V,
162 12 Y162C, Y162H,
146 13 V146A, V146M,
203 8
208 10 E208K,
168 10
202 11 I202T,
141 11 I141N, I141V,
167 13
853 15
161 8 E161K, E161Q,
201 9
219 6 c.656_657insATTCA, R219H, p.R219HfsX11, R219C,
225 9 R225W, R225Q,
151 10
218 8
207 8
212 14 L212P, L212Q,
215 13 p.L215CfsX10,
200 7
145 10
140 12
220 7 T220I,