KCNH2 Variant M579V Detail

We estimate the penetrance of LQTS for KCNH2 M579V is 16%. This variant was found in a total of 1 carriers in 0 papers or gnomAD, 0 had LQTS. M579V is present in 1 alleles in gnomAD. M579V 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 M579V around 16% (1/11).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density (%)
-1.396 0.0 0 0.456 23
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: - 1 1 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.

M579V 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
579 0 M579I, M579I, M579V, M579I, M579T,
578 4
580 4 D580Y,
577 5
581 5
576 7
582 7 R582P, R582C, R582H, R582L,
575 8 E575K,
583 8 I583V,
574 8 M574L, M574V, M574L,
584 8 G584C, G584R, G584S,
573 9
585 9 W585C, W585C,
572 10 G572D, G572C, G572S, G572R,
586 10 L586M,
571 11 I571V, I571L,
587 11
570 11
588 11 N588K, N588K, N588D,
569 12 Y569X, Y569C, Y569H,
589 12 L589P,
568 13 W568C, W568C,
590 13 G590D, G590V,
567 13 I567T, I567M,
591 13 D591H, D591N,
566 14 C566S, C566R, C566G, C566S, C566F,
592 14 Q592X,
565 14
593 14 I593T, I593R, I593V, I593X, I593K,
564 15 L564L,
594 15