KCNH2 Variant P361A Detail

We estimate the penetrance of LQTS for KCNH2 P361A is 12%. We are unaware of any observations of this variant in individuals. P361A is not present in gnomAD. P361A 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 P361A around 12% (1/10).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density (%)
-5.877 0.768 -1 0.84 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.

P361A 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
361 0
360 4
362 4
359 5 I359V,
363 5 I363X,
358 7
364 7 K364X,
357 8 E357D, E357D,
365 8 E365G,
356 8 R356C, R356H,
366 8 R366Q, R366X,
355 9 D355G,
367 9 T367S, T367S,
354 10
368 10 H368Y,
353 11 T353S, T353S,
369 11 N369K, N369K,
352 11
370 11
351 12 S351L,
371 12
350 13
372 13
349 13
373 13
348 14
374 14
347 14 P347S,
375 14
346 15 D346Y, D346E, D346E, D346N,
376 15 Q376sp, Q376R,