KCNH2 Variant P310L Detail

We estimate the penetrance of LQTS for KCNH2 P310L is 10%. This variant was found in a total of 1 carriers in 0 papers or gnomAD, 0 had LQTS. P310L is present in 1 alleles in gnomAD. P310L 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 1 individuals with LQT2 and 9 unaffected individuals.These data combined with observations of carriers lead us to estimate the LQTS penetrance for KCNQ1 P310L around 10% (1/11).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density (%)
-2.245 0.76 -2 0.633 4
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.

P310L 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
310 0 P310X, P310L,
309 4 H309Q, H309Y, H309Q,
311 4 L311R,
308 5 M308I, M308I, M308T, M308R, M308V, M308I,
312 5 R312C, R312H, R312Del,
307 7 A307P,
313 7
306 8 G306W,
314 8 G314S,
305 8
315 8
304 9 S304R, S304R, S304R,
316 9
303 10
317 10 N317S,
302 11 H302X, H302fsX, H302H,
318 11
301 11
319 11 T319T,
300 12
320 12 S320L, S320W, S320X,
299 13
321 13 D321Y,
298 13 P298X,
322 13
297 14 P297S,
323 14 D323E, D323E, D323N,
296 14 L296fsX,
324 14 L324L,
295 15 V295fsX,
325 15 V325M,