SCN5A Variant L1277R Detail

We estimate the penetrance of LQTS for SCN5A L1277R around 25% and the Brugada syndrome penetrance around 20%. SCN5A L1277R was found in a total of 0 carriers in 0 papers and/or in gnomAD: 0 had Brugada syndrome, 0 had LQTS. L1277R is not present in gnomAD. L1277R has been functionally characterized in 0 papers. This residue is located in a Mild_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 L1277R around 25% (1/10) and the Brugada syndrome penetrance around 20% (2/10).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density BrS (%) Penetrance Density LQT3 (%)
NA NA NA 0.976 21 31
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 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.

L1277R 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
1267 11
1271 11 W1271C,
1281 7 c.3840+1G>A, V1281F,
1304 12 T1304M,
1274 5
1285 14
1258 12
1272 9
1270 10 A1270S,
1283 11 L1283M,
1309 10 R1309H, R1309C,
1251 13 V1251M,
1279 7 V1279I,
1310 14
1306 11 R1306H, R1306S,
1305 8
1273 5 c.3816delG, W1273C,
1282 9 S1282A,
1302 10 p.L1302Vfs18,
1247 13 T1247I,
1257 14
1268 13 T1268N, T1268S,
1307 12
1275 7 D1275N,
1254 11
1263 15
1301 14
1253 13 E1253G,
1284 11
1280 6
1311 14 L1311P,
1308 10 L1308F,
1250 11
1269 12 N1269S,
1276 5
1278 5 I1278N,
1266 11
1277 0
1303 14 R1303Q, R1303W,