KCNH2 Variant D342E Detail

We estimate the penetrance of LQTS for KCNH2 D342E is 6%. We are unaware of any observations of this variant in individuals. D342E is not present in gnomAD. D342E 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 D342E around 6% (0/10).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density (%)
-0.684 0.33 2 0.408 0
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
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.

D342E 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
342 0 D342V, D342X, D342A,
341 4
343 4 L343fsX,
340 5 F340L, F340L, F340L,
344 5
339 7
345 7 G345S,
338 8
346 8 D346Y, D346N, D346E, D346E,
337 8 T337S, T337S, T337X,
347 8 P347S,
336 9
348 9
335 10 Q335X,
349 10
334 11 P334L,
350 11
333 11
351 11 S351L,
332 12
352 12
331 13 S331N, S331T,
353 13 T353S, T353S,
330 13 I330V,
354 13
329 14
355 14 D355G,
328 14 R328C, R328fsX, R328H,
356 14 R356C, R356H,
327 15 Y327H,
357 15 E357D, E357D,