KCNH2 Variant G572S Detail

We estimate the penetrance of LQTS for KCNH2 G572S is 92%. This variant was found in a total of 38 carriers in 21 papers or gnomAD, 36 had LQTS. G572S is not present in gnomAD. G572S has been functionally characterized in 2 papers. 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 8 individuals with LQT2 and 2 unaffected individuals.These data combined with observations of carriers lead us to estimate the LQTS penetrance for KCNQ1 G572S around 92% (44/48).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density (%)
-5.632 0.999 0 0.959 88
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
21216356 2011 1 0 1
22727609 2012 1 0 1
Japan Cohort 2020 12 1 11
21308345 2010 5 1 4
20197117 2010 4 0 2
France Cohort 2020 3 0 3
19038855 2009 1 0 1 Seizure
15176425 2004 2 0 2
15840476 2005 2 0 2
17905336 2007 1 0 1
19996378 2009 1 0 1
19306396 2009 3 0 3
19490267 2009 1 0 1
21063070 2010 1 0 1
24217263 2013 1 0 congenital LQT
26496715 2015 2 0 2
27871843 2017 1 0 1
28532774 2017 1 0 1
29622001 2018 2 0 2
29650123 2018 1 0
None 0 1
LITERATURE, COHORT, AND GNOMAD: - 38 2 36 -
VARIANT FEATURES ALONE: - 10 2 8 -
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)
19490267 HEK293 None None None None
28082916 HEK293 16 0.0 None None 2.111111111

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)
19490267 HEK293 11 None None None
28082916 HEK293 None None None

G572S 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
572 0 G572C, G572R, G572D, G572S,
573 4
571 4 I571L, I571V,
570 5
575 6 E575K,
569 6 Y569X, Y569C, Y569H,
586 6 L586M,
576 6
585 6 W585C, W585C,
574 6 M574L, M574L, M574V,
568 7 W568C, W568C,
584 8 G584R, G584C, G584S,
637 8 E637X, E637G, E637K,
636 9
587 9
634 9 T634S, T634P, T634I, T634A, T634S,
577 10
567 10 I567M, I567T,
610 10
583 10 I583V,
430 11
431 11 F431L, F431L, F431L,
566 11 C566S, C566F, C566G, C566S, C566R,
614 11 A614V, A614T,
565 11
640 11 F640L, F640L, F640L, F640V, F640Del,
589 12 L589P,
633 12 N633I, N633S, N633D,
588 12 N588K, N588K, N588D,
597 12 Y597C, Y597H,
632 12 P632A, P632S,
613 12 T613L, T613A, T613M, T613K,
635 12 N635I,
605 12 P605L,
631 13 S631F,
617 13 F617L, F617L, F617L, F617V,
630 13 V630T, V630A, V630I,
638 13 K638E, K638D, K638R, K638Del,
590 13 G590D, G590V,
607 14
639 14 I639F, I639N,
564 14 L564L,
609 14 D609N, D609G,
604 14 G604S, G604D, G604C,
429 14 A429P, A429V,
611 14 Y611D,
432 14
641 14 S641F, S641P,
606 15 S606F, S606Del, S606P,
618 15 T618S, T618S,
603 15 G603D,