KCNH2 Variant S919R Detail

We estimate the penetrance of LQTS for KCNH2 S919R is 8%. This variant was found in a total of 1 carriers in 0 papers or gnomAD (version 4), 0 had LQTS. S919R is present in 1 alleles in gnomAD. We have tested the trafficking efficiency of this variant, 88% of WT with a standard error of 14%; in our analysis we used SE < 20% as 'high quality'. Approximately below 50% of WT is considered PS3 moderate and below 30% is PS3 strong. S919R has not been functionally characterized. This residue is located in a Mild_Hotspot region for LQT2. In silico predictions, functional data (if available), and location in structure are equivalent to observing 0 individuals with LQT2 and 10 unaffected individuals.These data combined with observations of carriers lead us to estimate the LQTS penetrance for KCNQ1 S919R around 8% (0/11).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density (%)
-0.406 0.072 1 0.45 15
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 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 LQT2 Other Disease
LITERATURE, COHORT, AND GNOMAD: - 1 0 0 -
VARIANT FEATURES ALONE: - 10 10 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.

S919R 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. NOTE: some residues appear multiple times at different distances since the functional KV11.1 channel (protein product of KCNH2/hERG) is a homotetramer and occasionally the same residue from multiple subunits is present within the 15A window. 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
919 0
918 4
920 4 R920W, R920fsX, R920Q, R920G,
917 5 P917L,
921 5
916 7
922 7 R922W, R922fsX, R922Q,
915 8 A915X, A915fsX, A915V,
923 8 P923X, P923Q, P923L, P923fsX,
914 8
924 8 G924A, G924W, G924V, G924X, G924E,
913 9 A913V,
925 9 G925R, G925R, G925fsX, G925E, G925X, G925V, G925A,
912 10 R912W, R912X, R912Q,
926 10 P926S, P926L, P926fsX, P926X,
911 11 G911X,
927 11 W927X, W927G, W927C, W927L, W927C, W927S,
910 11 P910fsX, P910L,
928 11 G928E, G928fsX,
909 12 G909X,
929 12
908 13 L908X, L908fsX,
930 13
907 13 A907X,
931 13 P931L,
906 14 S906L,
932 14
905 14 V905M,
933 14
904 15 E904X,
934 15