KCNQ1 Variant R519P Detail

We estimate the penetrance of LQTS for KCNQ1 R519P is 16%. We are unaware of any observations of this variant in individuals. R519P is not present in gnomAD. R519P has not been functionally characterized. This residue is located in a Mild_Hotspot region for LQT1. In silico predictions, functional data (if available), and location in structure are equivalent to observing 1 individuals with LQT1 and 9 unaffected individuals. These data combined with observations of carriers lead us to estimate the LQTS penetrance for KCNQ1 R519P around 16% (1/10).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density (%)
-4.78 0.895 -3 0.902 13
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 LQT1 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.

R519P 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. This results from the fact that the functional KV7.1 channel 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
519 0 R519H, R519C,
516 5
523 6
515 6
520 6 M520R,
381 7 C381Y,
522 7 Y522S,
517 8 I517T,
518 8 R518Q, R518G,
521 8
377 10
384 10
378 10 A378T,
514 10 I514T,
512 10
524 11 V524G,
513 11 T513A, T513S, T513S,
380 11 R380S, R380S, R380G,
385 11 E385K,
526 11 K526Q, K526E,
525 12 A525T, A525V,
383 12
374 13 L374H, L374F,
382 13
392 14 W392R, W392R, W392ins,
379 14 W379R, W379R, W379C, W379C, W379G,
527 14
373 14 S373P,
511 14 R511Q, R511W,
376 15
375 15