SCN5A Variant I1235T Detail

We estimate the penetrance of LQTS for SCN5A I1235T around 4% and the Brugada syndrome penetrance around 33%. SCN5A I1235T was found in a total of 0 carriers in 0 papers and/or in gnomAD: 0 had Brugada syndrome, 0 had LQTS. I1235T is not present in gnomAD. I1235T has been functionally characterized in 0 papers. This residue is located in a 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 (3 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 I1235T around 4% (0/10) and the Brugada syndrome penetrance around 33% (3/10).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density BrS (%) Penetrance Density LQT3 (%)
NA NA NA 0.839 45 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 12 0 3 - -
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.

I1235T has 35 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 14 M1245I,
1233 8 K1233E,
1218 13 S1218I, S1218T,
1217 14
1243 12 D1243N,
1234 4
1220 11 G1220E,
1673 15
1241 11
1226 10
1221 8 A1221V,
1242 10
1676 15 M1676T, M1676I,
1219 13 S1219N,
1239 5 L1239P,
1244 15 K1244E,
1235 0
1246 15
1231 9 E1231K,
1237 6 V1237F,
1228 9 Y1228C, Y1228H, Y1228F,
1223 10 c.3667delG,
1697 14
1222 10 p.L1222LfsX7, L1222R,
1230 9 E1230K,
1227 11
1229 6
1696 14
1224 8
1240 9 E1240Q,
1225 7 E1225K, G1225K,
1232 9 R1232Q, R1232W,
1238 5
1236 6 K1236R, K1236N,
1303 13 R1303Q, R1303W,