KCNH2 Variant P967L Detail

We estimate the penetrance of LQTS for KCNH2 P967L is 1%. This variant was found in a total of 91 carriers in 3 papers or gnomAD (version 4), 0 had LQTS. P967L is present in 90 alleles in gnomAD. We have tested the trafficking efficiency of this variant, 165% of WT with a standard error of 7%; 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. P967L has been functionally characterized in 1 papers. 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 P967L around 1% (0/101).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density (%)
-0.291 0.0 -1 0.352 0
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
14661677 2003 1 1
15913580 2005 1 0
29752375 2018 1 0 SIDS
LITERATURE, COHORT, AND GNOMAD: - 91 31 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.

Functional Data Homozygously Collected

Steady state (S.S.) and peak tail 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. Recovery from inactivation (Rec. inact.) and deactivation time (Deactivation) are the ratio of characteristic time constants with wildtype (unitless).

PubMed ID Cell Type S.S Peak (%WT) Peak Tail IKr (%WT) V1/2 Act. V1/2 Inact. Recov. Inact. Deactivation (%WT)
14975928 HEK293 121 -4.3 None 1.0 1.0

Functional Data Heterozygously Collected

Functional parameters are the same as defined above.

PubMed ID Cell Type S.S Peak (%WT) Peak Tail IKr (%WT) V1/2 Act. V1/2 Inact. Deactivation (%WT)
14975928 HEK293 None None None

P967L 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
967 0 P967X, P967L,
966 4 E966A, E966K,
968 4 P968fsX, P968A, P968L,
965 5 G965fsX, G965R, G965R, G965X,
969 5 G969X, G969D,
964 7 G964X,
970 7 G970A,
963 8 P963T,
971 8
962 8
972 8 P972S, P972H,
961 9 P961X,
973 9 L973X,
960 10 S960N,
974 10 M974L, M974L,
959 11
975 11
958 11 F958L, F958L, F958L,
976 11
957 12
977 12 C977W, C977Y, C977S, C977S, C977F,
956 13
978 13 E978X, E978K,
955 13 L955V,
979 13 K979R,
954 14 R954H, R954C,
980 14
953 14
981 14 S981N, S981G, S981X,
952 15 P952T, P952S,
982 15 D982N,