SCN5A Variant L1222R Detail

We estimate the penetrance of LQTS for SCN5A L1222R around 47% and the Brugada syndrome penetrance around 15%. SCN5A L1222R was found in a total of 1 carriers in 1 papers and/or in gnomAD: 0 had Brugada syndrome, 1 had LQTS. L1222R is not present in gnomAD. L1222R has been functionally characterized in 1 papers. This residue is located in a Mild_Hotspot region for Brugada syndrome and a 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 (1 with LQTS). These data combined with observations of carriers lead us to estimate the LQTS penetrance for SCN5A L1222R around 47% (2/11) and the Brugada syndrome penetrance around 15% (1/11).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density BrS (%) Penetrance Density LQT3 (%)
-5.82 0.926 -5.27 0.946 14 51
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
30059973 2018 1 1 0 0
LITERATURE, COHORT, AND GNOMAD: - 1 0 1 0 -
VARIANT FEATURES ALONE: - 15 13 1 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.

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

L1222R has 65 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
1245 13 M1245I,
1218 6 S1218I, S1218T,
1281 14 c.3840+1G>A, V1281F,
1304 8 T1304M,
1217 9
1243 10 D1243N,
1216 10 L1216V,
1234 14
1698 14 A1698T,
1285 15
1299 15 c.3894delC,
1220 5 G1220E,
1673 7
1675 12
1213 14
1241 13
1309 13 R1309H, R1309C,
1226 8
1669 9
1671 14
1221 4 A1221V,
1242 9
1668 15 M1668T,
1676 10 M1676T, M1676I,
1219 5 S1219N,
1672 10 S1672Y,
1239 7 L1239P,
1310 12
1306 8 R1306S, R1306H,
1665 14
1305 11
1246 11
1235 10
1282 14 S1282A,
1302 12 p.L1302Vfs18,
1247 14 T1247I,
1237 14 V1237F,
1701 14 M1701I,
1307 8
1228 13 Y1228F, Y1228H, Y1228C,
1678 14 N1678S,
1223 5 c.3667delG,
1697 10
1222 0 p.L1222LfsX7, L1222R,
1227 13
1300 15
1674 12 F1674V,
1229 11
1215 10 I1215V,
1301 10
1214 13 M1214T,
1696 12
1700 14
1677 11
1308 12 L1308F,
1250 14
1224 7
1670 11
1240 11 E1240Q,
1225 6 E1225K, G1225K,
1278 13 I1278N,
1238 11
1236 13 K1236R, K1236N,
1303 7 R1303Q, R1303W,
1666 13