SCN5A Variant L1217H Detail

We estimate the penetrance of LQTS for SCN5A L1217H around 8% and the Brugada syndrome penetrance around 26%. SCN5A L1217H was found in a total of 0 carriers in 0 papers and/or in gnomAD: 0 had Brugada syndrome, 0 had LQTS. L1217H is not present in gnomAD. L1217H 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 L1217H around 8% (0/10) and the Brugada syndrome penetrance around 26% (2/10).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density BrS (%) Penetrance Density LQT3 (%)
NA NA NA 0.938 31 7
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.

L1217H has 39 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,
1218 4 S1218I, S1218T,
1217 0
1243 13 D1243N,
1216 6 L1216V,
1220 6 G1220E,
1673 15
1213 5
1210 10 F1210S,
1241 12
1309 12 R1309C, R1309H,
1669 13
1221 7 A1221V,
1242 10
1219 6 S1219N,
1313 14
1239 11 L1239P,
1310 12
1306 11 R1306S, R1306H,
1246 8
1235 14
1247 14 T1247I,
1307 12
1223 11 c.3667delG,
1222 9 p.L1222LfsX7, L1222R,
1215 7 I1215V,
1206 15
1214 6 M1214T,
1212 10 p.I1212del,
1253 15 E1253G,
1211 10
1250 13
1224 11
1209 12 T1209R,
1240 15 E1240Q,
1225 14 G1225K, E1225K,
1238 12
1249 12 V1249D,
1303 14 R1303W, R1303Q,