SCN5A Variant L1229I Detail

We estimate the penetrance of LQTS for SCN5A L1229I around 5% and the Brugada syndrome penetrance around 18%. SCN5A L1229I was found in a total of 0 carriers in 0 papers and/or in gnomAD: 0 had Brugada syndrome, 0 had LQTS. L1229I is not present in gnomAD. L1229I 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 (1 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 L1229I around 5% (0/10) and the Brugada syndrome penetrance around 18% (1/10).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density BrS (%) Penetrance Density LQT3 (%)
NA NA NA 0.517 22 4
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 14 0 1 - -
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.

L1229I has 36 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
1233 7 K1233E,
1243 14 D1243N,
1234 9
1299 15 c.3894delC,
1220 14 G1220E,
1673 13
1681 12 c.5040_5042delTTAinsC, Y1681F,
1241 15
1226 7
1695 12 Q1695X,
1221 11 A1221V,
1242 13
1676 12 M1676T, M1676I,
1239 8 L1239P,
1680 13 A1680T, A1680P,
1235 6
1231 7 E1231K,
1237 9 V1237F,
1228 7 Y1228F, Y1228C, Y1228H,
1223 11 c.3667delG,
1697 13
1222 11 L1222R, p.L1222LfsX7,
1230 5 E1230K,
1227 7
1300 15
1229 0
1301 13
1696 12
1677 12
1224 10
1240 10 E1240Q,
1225 6 E1225K, G1225K,
1232 10 R1232W, R1232Q,
1238 10
1236 5 K1236N, K1236R,
1303 12 R1303Q, R1303W,