SCN5A Variant L1238R Detail

We estimate the penetrance of LQTS for SCN5A L1238R around 4% and the Brugada syndrome penetrance around 27%. SCN5A L1238R was found in a total of 0 carriers in 0 papers and/or in gnomAD: 0 had Brugada syndrome, 0 had LQTS. L1238R is not present in gnomAD. L1238R 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 L1238R around 4% (0/10) and the Brugada syndrome penetrance around 27% (2/10).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density BrS (%) Penetrance Density LQT3 (%)
NA NA NA 0.898 34 1
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.

L1238R has 32 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
1231 14 E1231K,
1241 6
1245 10 M1245I,
1247 15 T1247I,
1233 10 K1233E,
1226 14
1237 4 V1237F,
1228 15 Y1228H, Y1228C, Y1228F,
1218 11 S1218I, S1218T,
1223 13 c.3667delG,
1221 9 A1221V,
1224 11
1242 7
1217 12
1222 11 p.L1222LfsX7, L1222R,
1230 13 E1230K,
1243 10 D1243N,
1219 14 S1219N,
1240 7 E1240Q,
1235 5
1234 6
1229 10
1225 11 G1225K, E1225K,
1239 5 L1239P,
1232 13 R1232Q, R1232W,
1220 12 G1220E,
1306 15 R1306S, R1306H,
1244 11 K1244E,
1238 0
1236 8 K1236N, K1236R,
1303 13 R1303W, R1303Q,
1246 11