KCNQ1 Variant E663K

Summary of observed carriers, functional annotations, and structural context for KCNQ1 E663K. Data combine curated literature, international cohorts, and gnomAD observations.

Estimated LQT1 penetrance

10%

1/12 effective observations

Total carriers

2

0 LQT1 · 2 unaffected

Functional studies

0

Publications with functional data

E663K is present in 2 alleles in gnomAD. This residue resides in a Non_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 (%)
-0.8 0.998 0 0.635 0

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 – 2 2 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 E663K.
Neighbour residue Distance (Å) Observed variants
663 0 E663K,
662 4
664 4
661 5
665 5
660 7 P660S,
666 7
659 8
667 8 V667M
658 8 T658N,
668 8
657 9 N657S,
669 9 R669S, R669S, R669T,
656 10
670 10 R670K,
655 11
671 11 G671S,
654 11
672 11
653 12 F653Y,
673 12 D673N,
652 13
674 13 E674K,
651 13
675 13
650 14
649 14 D649N, D649G,
648 15 V648I,