SCN5A Variant L1239I Detail

We estimate the penetrance of LQTS for SCN5A L1239I around 3% and the Brugada syndrome penetrance around 29%. SCN5A L1239I was found in a total of 0 carriers in 0 papers and/or in gnomAD: 0 had Brugada syndrome, 0 had LQTS. L1239I is not present in gnomAD. L1239I has been functionally characterized in 0 papers. This residue is located in a Mild_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 (2 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 L1239I around 3% (0/10) and the Brugada syndrome penetrance around 29% (2/10).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density BrS (%) Penetrance Density LQT3 (%)
NA NA NA 0.787 39 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: - 0 0 0 0 -
VARIANT FEATURES ALONE: - 15 13 0 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.

L1239I has 50 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 10 M1245I,
1233 11 K1233E,
1218 9 S1218T, S1218I,
1304 12 T1304M,
1217 11
1243 7 D1243N,
1216 15 L1216V,
1234 9
1285 13
1299 14 c.3894delC,
1220 10 G1220E,
1673 13
1241 8
1226 10
1221 6 A1221V,
1242 6
1676 14 M1676I, M1676T,
1219 10 S1219N,
1239 0 L1239P,
1306 11 R1306S, R1306H,
1244 11 K1244E,
1282 14 S1282A,
1246 10
1235 5
1302 14 p.L1302Vfs18,
1231 14 E1231K,
1247 13 T1247I,
1237 7 V1237F,
1307 14
1289 14
1228 13 Y1228F, Y1228C, Y1228H,
1223 10 c.3667delG,
1697 15
1222 7 L1222R, p.L1222LfsX7,
1230 12 E1230K,
1227 13
1229 8
1215 14 I1215V,
1301 12
1214 14 M1214T,
1677 14
1250 15
1224 9
1240 5 E1240Q,
1248 15
1225 6 G1225K, E1225K,
1232 14 R1232W, R1232Q,
1238 5
1236 7 K1236N, K1236R,
1303 8 R1303W, R1303Q,