KCNH2 Variant S706Y Detail

We estimate the penetrance of LQTS for KCNH2 S706Y is 38%. We are unaware of any observations of this variant in individuals. S706Y is not present in gnomAD. S706Y has not been functionally characterized. This residue is located in a Hotspot region for LQT2. In silico predictions, functional data (if available), and location in structure are equivalent to observing 3 individuals with LQT2 and 7 unaffected individuals.These data combined with observations of carriers lead us to estimate the LQTS penetrance for KCNQ1 S706Y around 38% (3/10).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density (%)
-5.149 0.997 -2 0.918 42
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 7 3 -
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.

S706Y has 51 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
706 0 S706F, S706C,
705 5 W705X, W705fsX,
704 5 A704V, A704T,
703 6
709 6
707 6
708 6
702 7
710 8
701 9
4 9
673 10
686 10
478 10 A478D,
700 10
711 10 I711V,
762 11
669 11 G669C, G669X, G669R,
827 11
699 11 E699D, E699D,
670 12
764 12
672 12 R672H, R672C,
479 12
682 12 E682X,
713 13 M713V,
476 13 V476I,
677 13 M677T,
477 13
676 13 Q676X, Q676fsX,
763 13
481 13
6 13 G6R,
698 13 E698K, E698X,
712 14 D712N,
687 14
674 14 H674fsX, H674Y,
685 14 R685C, R685P, R685H,
668 14 S668L,
480 14 E480V,
3 14
765 14
829 14 D829E, D829E, D829A,
719 14
671 14 A671Del, A671G,
697 15 L697X,
540 15 D540fsX,
720 15
761 15
683 15
760 15