KCNH2 Variant F701L Detail

We estimate the penetrance of LQTS for KCNH2 F701L is 11%. We are unaware of any observations of this variant in individuals. F701L is not present in gnomAD. F701L 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 1 individuals with LQT2 and 9 unaffected individuals.These data combined with observations of carriers lead us to estimate the LQTS penetrance for KCNQ1 F701L around 11% (1/10).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density (%)
-5.733 0.969 0 0.901 11
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 9 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.

F701L has 58 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
701 0
702 5
704 6 A704V, A704T,
677 6 M677T,
700 6
705 7 W705fsX, W705X,
676 7 Q676X, Q676fsX,
673 7
698 7 E698K, E698X,
697 7 L697X,
680 7
703 8
720 8
699 9 E699D, E699D,
706 9 S706F, S706C,
719 9
710 10
708 10
716 10 V716G,
4 10
681 10 R681W,
679 10 R679Q, R679W,
674 11 H674Y, H674fsX,
675 11
672 11 R672C, R672H,
678 11
709 11
707 12
721 12 P721L,
724 12 L724X,
683 12
694 12 R694C, R694H,
669 12 G669C, G669R, G669X,
696 12 R696C, R696H,
684 12
711 12 I711V,
717 12 L717P,
3 13
670 13
695 13
5 13
764 13
715 13 A715T, A715A, A715sp, A715V,
671 13 A671Del, A671G,
693 13 L693X,
712 13 D712N,
6 13 G6R,
718 14
682 14 E682X,
762 14
544 14 E544A, E544fsX,
725 14 Q725R, Q725fsX,
728 14
540 14 D540fsX,
767 14 D767X,
689 15
763 15
713 15 M713V,