KCNQ1 Variant H455R

Summary of observed carriers, functional annotations, and structural context for KCNQ1 H455R. Data combine curated literature, international cohorts, and gnomAD observations.

Estimated LQT1 penetrance

15%

1/11 effective observations

Total carriers

1

0 LQT1 · 1 unaffected

Functional studies

0

Publications with functional data

H455R is present in 1 alleles in gnomAD. This residue resides in a Mild_Hotspot region for LQT1.

Variant features alone are equivalent to phenotyping 1 individuals with LQT1 and 9 unaffected individuals.

In silico predictors

Variant-level computational predictors.
PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density LQT1 (%)
-0.45 0.0 -2 0.626 17

PROVEAN scores below -2 suggest deleterious impact. REVEL scores above 0.5–0.75 are often interpreted as likely pathogenic. PolyPhen-2 scores above 0.85 are typically pathogenic. BLAST-PSSM reflects evolutionary conservation; more negative values indicate rarer substitutions. Penetrance density summarises neighbouring residue risk (Kroncke et al. 2019).

Reported carrier data

Observed carriers by publication or cohort.
Source Year Carriers Unaffected LQT1 Other Disease
Literature, cohort, and gnomAD 1 1 0
Variant features alone 15 9 1

Totals may differ from individual publications due to duplicate patients removed during curation.

Nearby variants

Neighbouring residues within 15 Ångström provide structural context. Variants listed in the right-most column have been observed clinically or in gnomAD.

Previously observed variants near H455R.
Neighbour residue Distance (Å) Observed variants
455 0 H455Y, H455Q, H455Q, H455R,
454 4
456 4 F456L, F456L, F456L,
453 5
457 5
452 7 R452Q, R452W, R452L,
458 7
451 8 R451Q, R451W,
459 8 D459N, D459V,
450 8 E450K,
460 8 G460S, G460D, G460C,
449 9 E449K,
461 9
448 10 P448R, P448Q, P448L, P448S,
462 10 D462N
447 11 P447H,
463 11 S463T,
446 11 D446E, D446E, D446E, D446E, D446N,
464 11 S464P,
445 12
465 12
444 13 T444M, T444K,
466 13
443 13
467 13 K467R,
442 14 H442R,
468 14 S468G, S468N,
441 14 P441S,
469 14
440 15
470 15