SCN5A Variant I1212L Detail

We estimate the penetrance of LQTS for SCN5A I1212L around 29% and the Brugada syndrome penetrance around 26%. SCN5A I1212L was found in a total of 0 carriers in 0 papers and/or in gnomAD: 0 had Brugada syndrome, 0 had LQTS. I1212L is not present in gnomAD. I1212L 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 I1212L around 29% (1/10) 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 0.63 34 37
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.

I1212L has 42 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
1271 13 W1271C,
1218 11 S1218I, S1218T,
1217 10
1315 11
1274 14
1216 6 L1216V,
1314 10 c.3940_3941delCT,
1220 13 G1220E,
1320 15 M1320I,
1213 6
1666 13
1272 14
1210 7 F1210S,
1309 8 R1309C, R1309H,
1669 15
1219 11 S1219N,
1313 6
1310 8
1316 9 R1316Q, R1316L,
1207 9
1306 13 R1306S, R1306H,
1246 12
1662 14
1317 12 F1317C,
1257 13
1307 12
1275 12 D1275N,
1321 15 R1321K,
1215 5 I1215V,
1206 10
1214 7 M1214T,
1212 0 p.I1212del,
1253 11 E1253G,
1211 5
1312 9
1311 11 L1311P,
1308 13 L1308F,
1250 12
1209 5 T1209R,
1278 15 I1278N,
1249 13 V1249D,
1208 7 E1208X, E1208K,