KCNH2 Variant L311R Detail

We estimate the penetrance of LQTS for KCNH2 L311R is 9%. This variant was found in a total of 1 carriers in 0 papers or gnomAD, 0 had LQTS. L311R is present in 1 alleles in gnomAD. L311R 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 L311R around 9% (1/11).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density (%)
-2.04 0.093 0 0.707 7
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.

L311R 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
311 0 L311R,
310 4 P310L, P310X,
312 4 R312H, R312Del, R312C,
309 5 H309Y, H309Q, H309Q,
313 5
308 7 M308I, M308I, M308T, M308V, M308I, M308R,
314 7 G314S,
307 8 A307P,
315 8
306 8 G306W,
316 8
305 9
317 9 N317S,
304 10 S304R, S304R, S304R,
318 10
303 11
319 11 T319T,
302 11 H302H, H302X, H302fsX,
320 11 S320X, S320L, S320W,
301 12
321 12 D321Y,
300 13
322 13
299 13
323 13 D323N, D323E, D323E,
298 14 P298X,
324 14 L324L,
297 14 P297S,
325 14 V325M,
296 15 L296fsX,
326 15 R326C, R326H, R326fsX,