SCN5A Variant P1803Q Detail

We estimate the penetrance of LQTS for SCN5A P1803Q around 16% and the Brugada syndrome penetrance around 19%. SCN5A P1803Q was found in a total of 0 carriers in 0 papers and/or in gnomAD: 0 had Brugada syndrome, 0 had LQTS. P1803Q is not present in gnomAD. P1803Q has been functionally characterized in 0 papers. This residue is located in a Mild_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 (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 P1803Q around 16% (0/10) and the Brugada syndrome penetrance around 19% (1/10).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density BrS (%) Penetrance Density LQT3 (%)
NA NA NA 0.845 21 19
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.

P1803Q has 35 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
1850 14 C1850S,
1803 0
1794 14
1849 15 H1849R,
1806 8 p.Thr1806SerfsX27,
1795 13 Y1795H, Y1795C, Y1795N, p.Y1795_E1796insD,
1512 11 R1512L, R1512Q, R1512W,
1813 12
1801 8
1511 9
1802 4
1522 13
1510 10
1523 15 D1523N,
1507 10 p.Q1507_P1509del,
1509 6 P1509T,
1808 12
1804 4
1807 11 c.5420dupA,
1526 14 T1526P,
1798 9 W1798X,
1585 14 Y1585C,
1797 12 I1797V,
1800 8
1817 13
1796 12
1799 7
1513 14
1508 10
1816 15 D1816N, D1816E, c.5445_5446insT,
1805 7
1810 12
1809 11 I1809M,
1506 11 P1506T, P1506S,
1847 14 R1847H, R1847C,