SCN5A Variant R1638Q Detail

We estimate the penetrance of LQTS for SCN5A R1638Q around 4% and the Brugada syndrome penetrance around 8%. SCN5A R1638Q was found in a total of 2 carriers in 0 papers and/or in gnomAD: 0 had Brugada syndrome, 0 had LQTS. R1638Q is present in 2 alleles in gnomAD. R1638Q 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 (0 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 R1638Q around 4% (0/12) and the Brugada syndrome penetrance around 8% (0/12).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density BrS (%) Penetrance Density LQT3 (%)
-2.18 1 0.13 0.785 7 6
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 15 0 0 - -
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.

R1638Q has 41 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
1794 14
1643 11 I1643L,
1795 15 Y1795N, Y1795C, p.Y1795_E1796insD, Y1795H,
1531 12
1635 8
1634 10 L1634P,
1820 14 A1820V, A1820T,
1641 8
1639 6 G1639A,
1787 12 S1787N,
1648 12
1532 13 V1532F, V1532I,
1821 14
1644 6 R1644L, R1644C, R1644H,
1640 9
1797 12 I1797V,
1800 14
1793 8 M1793K,
1789 7
1632 14 R1632H, R1632L, R1632C,
1645 11 T1645M,
1796 9
1535 14
1799 15
1788 12 c.5361_5364delTGAG,
1638 0 R1638X, R1638Q,
1651 14
1633 11
1791 14
1637 6
1792 9 D1792N, D1792V, D1792Y,
1636 7
1823 14 E1823K, p.E1823HfsX10,
1642 11 G1642E,
1528 11
1790 11 D1790G, D1790N, p.D1790del,
1631 14 G1631D,
252 15
1647 11
1822 11 c.5464-5467delTCTG, c.5464_5467delTCTG,
1646 14