SCN5A Variant R1897Q Detail

We estimate the penetrance of LQTS for SCN5A R1897Q around 11% and the Brugada syndrome penetrance around 12%. SCN5A R1897Q was found in a total of 7 carriers in 1 papers and/or in gnomAD: 0 had Brugada syndrome, 1 had LQTS. R1897Q is present in 6 alleles in gnomAD. R1897Q has been functionally characterized in 1 papers. This residue is located in a Mild_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 R1897Q around 11% (1/17) and the Brugada syndrome penetrance around 12% (1/17).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density BrS (%) Penetrance Density LQT3 (%)
-2.58 0.982 0.68 0.696 25 4
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
27485560 2016 1 1 0 0
LITERATURE, COHORT, AND GNOMAD: - 7 6 1 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.

Functional Data

Peak and late/persistent current are relative to wildtype (100% being no different from wildtype). V0.5 act/inact are the voltages at which half of the maximal current is reached during an activation and inactivation protocol, each is in units of mV and relative to wildtype.
PubMed ID Year Cell Type Peak Current (%WT) V1/2 Act. (mV) V1/2 Inact. (mV) Late/Persistent Current (%WT)
27485560 2016

R1897Q has 31 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
1882 15
1883 14
1884 14 P1884L,
1885 13
1886 13
1887 12
1888 11
1889 11 Y1889C,
1890 10 E1890K,
1891 9
1892 8
1893 8 c.5676delC,
1894 7
1895 5 T1895I,
1896 4 L1896P, p.L1896PfsX47,
1897 0 R1897Y, R1897W, R1897Q,
1898 4 R1898C, R1898H,
1899 5
1900 7
1901 8 E1901K, E1901Q,
1902 8 E1902A,
1903 9 V1903M,
1904 10 S1904L,
1905 11
1906 11 M1906V, M1906T,
1907 12
1908 13 I1908V,
1909 13 Q1909R,
1910 14 R1910K,
1911 14
1912 15