KCNH2 Variant L1049F Detail

We estimate the penetrance of LQTS for KCNH2 L1049F is 9%. We are unaware of any observations of this variant in individuals. L1049F is not present in gnomAD. We have tested the trafficking efficiency of this variant, 102% of WT with a standard error of 11%; 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. L1049F 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 L1049F around 9% (0/10).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density (%)
-2.969 0.998 -1 0.72 5
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: - 0 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.

L1049F 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
1049 0
1048 4
1050 4
1047 5 R1047H, R1047C, R1047L,
1051 5
1046 7 Q1046X,
1052 7
1045 8 L1045F,
1053 8 E1053fsX, E1053X,
1044 8
1054 8 T1054fsX,
1043 9 D1043G,
1055 9 R1055W, R1055Q,
1042 10
1056 10 L1056fsX,
1041 11
1057 11 S1057N, S1057fsX,
1040 11
1058 11 A1058T, A1058E,
1039 12 E1039X,
1059 12 D1059E, D1059E,
1038 13 V1038L, V1038X, V1038L, V1038M, V1038fsX,
1060 13 M1060V, M1060I, M1060I, M1060I,
1037 13 D1037fsX, D1037E, D1037N, D1037E, D1037X,
1061 13 A1061P,
1036 14 G1036D, G1036fsX, G1036X, G1036Del,
1062 14 T1062X, T1062P, T1062I,
1035 14 R1035fsX, R1035Q, R1035W, R1035X,
1063 14 V1063L, V1063I,
1034 15 P1034fsX, P1034X,
1064 15 L1064X,