KCNH2 Variant S304R Detail

We estimate the penetrance of LQTS for KCNH2 S304R is 9%. This variant was found in a total of 1 carriers in 0 papers or gnomAD, 0 had LQTS. S304R is present in 1 alleles in gnomAD. S304R 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 S304R around 9% (0/11).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density (%)
-1.678 0.192 -1 0.79 5
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 10 0 -
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.

S304R 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
304 0 S304R, S304R, S304R,
303 4
305 4
302 5 H302X, H302H, H302fsX,
306 5 G306W,
301 7
307 7 A307P,
300 8
308 8 M308T, M308I, M308I, M308V, M308I, M308R,
299 8
309 8 H309Y, H309Q, H309Q,
298 9 P298X,
310 9 P310L, P310X,
297 10 P297S,
311 10 L311R,
296 11 L296fsX,
312 11 R312H, R312Del, R312C,
295 11 V295fsX,
313 11
294 12
314 12 G314S,
293 13
315 13
292 13
316 13
291 14
317 14 N317S,
290 14
318 14
289 15 E289K,
319 15 T319T,