SCN5A Variant F1648C Detail

We estimate the penetrance of LQTS for SCN5A F1648C around 29% and the Brugada syndrome penetrance around 32%. SCN5A F1648C was found in a total of 0 carriers in 0 papers and/or in gnomAD: 0 had Brugada syndrome, 0 had LQTS. F1648C is not present in gnomAD. F1648C 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 (3 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 F1648C around 29% (1/10) and the Brugada syndrome penetrance around 32% (3/10).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density BrS (%) Penetrance Density LQT3 (%)
NA NA NA 0.964 42 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 11 1 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.

F1648C has 55 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
403 13
1785 14
1643 10 I1643L,
1778 7
1773 14
1653 9
1635 14
1771 12 I1771T,
1652 5 M1652T, M1652R,
1634 11 L1634P,
1777 10 V1777M, V1777L,
1650 7 L1650F,
1504 14 K1504E,
1656 14
1641 11
1639 14 G1639A,
1779 11 T1779M,
1776 12
1787 8 S1787N,
1654 10
1786 12 L1786R, L1786Q, c.5356_5357delCT,
1648 0
1649 4 A1649V,
1774 9 N1774D, c.5321_5324dupACTT,
1644 7 R1644H, R1644C, R1644L,
1640 13
256 14
1657 14
1496 13
1793 14 M1793K,
1781 10 E1781D, E1781G,
1789 8
1772 14 L1772V,
1645 6 T1645M,
410 15 A410V,
1780 14 E1780G,
1788 6 c.5361_5364delTGAG,
1770 13 I1770V,
1638 12 R1638X, R1638Q,
1651 5
1500 11 p.K1500del,
1791 12
1637 11
1792 10 D1792Y, D1792V, D1792N,
407 13
1783 15
1775 10 F1775V, p.F1775LfsX15,
1642 11 G1642E,
1655 12
1497 14
1790 11 p.D1790del, D1790G, D1790N,
1647 7
1503 15 S1503Y,
1646 8
1782 11