SCN5A Variant S1744I Detail

We estimate the penetrance of LQTS for SCN5A S1744I around 7% and the Brugada syndrome penetrance around 19%. SCN5A S1744I was found in a total of 2 carriers in 0 papers and/or in gnomAD: 0 had Brugada syndrome, 0 had LQTS. S1744I is present in 2 alleles in gnomAD. S1744I has been functionally characterized in 0 papers. This residue is located in a 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 (0 with LQTS). These data combined with observations of carriers lead us to estimate the LQTS penetrance for SCN5A S1744I around 7% (0/12) and the Brugada syndrome penetrance around 19% (2/12).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density BrS (%) Penetrance Density LQT3 (%)
-4.33 1 -2.91 0.853 25 12
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: - 2 2 0 0 -
VARIANT FEATURES ALONE: - 15 13 0 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.

S1744I has 54 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 6 A1746T, A1746V,
1724 12
1741 11 D1741E, D1741N, D1741Y,
1715 13
1687 15
1745 4
1675 10
1743 4 G1743R, G1743E,
1723 11 T1723N,
1754 14
1725 13 P1725L,
1681 13 c.5040_5042delTTAinsC, Y1681F,
1694 11
1410 14
1747 5 V1747M,
1716 12 p.L1716SfsX71,
1695 15 Q1695X,
1714 14 D1714G,
1688 13
1671 15
1676 13 M1676T, M1676I,
1744 0 S1744I,
1721 5
1753 13 T1753A,
1742 7
1693 14
1680 10 A1680P, A1680T,
1719 8
1731 12
1728 12 C1728R, C1728Y, C1728W,
1678 8 N1678S,
1300 14
1674 12 F1674V,
1399 13
1748 6 p.G1748del, G1748D,
1730 15 P1730H, P1730A, P1730L,
1683 10
1718 10 S1718R,
1739 14 R1739W, R1739Q,
1717 9 L1717P,
1751 10
1677 11
1682 8
1750 10 L1750F,
1752 10
1722 6 N1722D,
1686 14
1749 8 I1749N,
1729 15 D1729N,
1740 11 G1740R,
1720 5 c.5157delC,
1732 12
1679 7
1685 12