KCNH2 Variant S981G Detail

We estimate the penetrance of LQTS for KCNH2 S981G is 0%. This variant was found in a total of 229 carriers in 0 papers or gnomAD (version 4), 0 had LQTS. S981G is present in 229 alleles in gnomAD. We have tested the trafficking efficiency of this variant, 104% of WT with a standard error of 6%; 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. S981G has not been functionally characterized. This residue is located in a Non_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 S981G around 0% (0/239).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density (%)
-0.265 0.001 3 0.534 2
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: - 229 75 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.

S981G 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
981 0 S981X, S981N, S981G,
980 4
982 4 D982N,
979 5 K979R,
983 5 T983I, T983X,
978 7 E978K, E978X,
984 7 C984fsX,
977 8 C977S, C977F, C977S, C977Y, C977W,
985 8 N985X, N985S,
976 8
986 8 P986L, P986T, P986fsX,
975 9
987 9 L987X, L987fsX, L987P,
974 10 M974L, M974L,
988 10 S988P, S988A, S988L,
973 11 L973X,
989 11 G989S, G989D,
972 11 P972H, P972S,
990 11 A990T,
971 12
991 12 F991fsX,
970 13 G970A,
992 13
969 13 G969X, G969D,
993 13
968 14 P968fsX, P968L, P968A,
994 14
967 14 P967L, P967X,
995 14
966 15 E966A, E966K,
996 15 N996X, N996I,