SCN5A Variant A1677T Detail

We estimate the penetrance of LQTS for SCN5A A1677T around 3% and the Brugada syndrome penetrance around 12%. SCN5A A1677T was found in a total of 0 carriers in 0 papers and/or in gnomAD: 0 had Brugada syndrome, 0 had LQTS. A1677T is not present in gnomAD. A1677T has been functionally characterized in 0 papers. This residue is located in a Non_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 A1677T around 3% (0/10) and the Brugada syndrome penetrance around 12% (1/10).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density BrS (%) Penetrance Density LQT3 (%)
NA NA NA 0.702 8 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 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.

A1677T has 61 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
1746 14 A1746T, A1746V,
1741 14 D1741Y, D1741N, D1741E,
1304 8 T1304M,
1698 15 A1698T,
1745 14
1299 12 c.3894delC,
1673 7
1675 5
1743 12 G1743E, G1743R,
1681 11 c.5040_5042delTTAinsC, Y1681F,
1694 9
1704 14 L1704H,
1298 13 P1298L,
1226 7
1747 10 V1747M,
1695 10 Q1695X,
1669 13
1671 11
1221 15 A1221V,
1676 5 M1676T, M1676I,
1744 11 S1744I,
1219 15 S1219N,
1672 9 S1672Y,
1742 13
1693 13
1699 14
1239 14 L1239P,
1306 14 R1306S, R1306H,
1305 12
1680 7 A1680T, A1680P,
1703 15
1302 11 p.L1302Vfs18,
1701 15 M1701I,
1307 13
1228 14 Y1228C, Y1228F, Y1228H,
1678 4 N1678S,
1223 12 c.3667delG,
1697 13
1222 11 L1222R, p.L1222LfsX7,
1227 10
1300 8
1674 6 F1674V,
1229 12
1748 12 p.G1748del, G1748D,
1301 6
1696 11
1700 11
1751 11
1677 0
1682 11
1308 15 L1308F,
1750 14 L1750F,
1752 14
1224 14
1670 12
1740 12 G1740R,
1225 9 E1225K, G1225K,
1720 13 c.5157delC,
1732 14
1679 6
1303 11 R1303Q, R1303W,