KCNQ1 Variant G643S

Summary of observed carriers, functional annotations, and structural context for KCNQ1 G643S. Data combine curated literature, international cohorts, and gnomAD observations.

Estimated LQT1 penetrance

0%

4/1569 effective observations

Total carriers

1559

3 LQT1 · 1556 unaffected

Functional studies

1

Publications with functional data

G643S is present in 1433 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 (%)
2

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
33552729 2021 1 1 0 DCM
32145446 2020 1 None None None
31751991 2020 3 None None Acute MI
29855564 2018 7 None None None
29197658 2018 11 None 11 None
27325960 2010 2 2 None Lone AF
26385840 2015 1 None None None
26118593 2015 1 None 1 None
24573873 2007 3 1 2 None
24363352 2014 8 None None None
24284363 2014 6 6 None 6 sudden death w/ psychotropic drugs, perhaps not SCD
23714088 2013 1 None None None
22949429 2012 32 32 None None
21139297 2010 1 1 None TdP after MI - AF history
19841300 2009 32 32 None None
17016049 2007 140 140 None atrial fibrillation
16723781 2006 88 81 0 None
15028050 2004 5 None 5 None
11761407 2001 12 7 5 None
Literature, cohort, and gnomAD 1559 1556 3
Variant features alone 15 9 1

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

Functional data

Functional assay results from published electrophysiology studies. HM indicates homomeric channels, HT indicates heteromeric channels.

Homomeric channel data

Published electrophysiology measurements (homomeric).
PubMed ID Year Study Type Assay Temperature Cell Type Result

Heteromeric channel data

Published electrophysiology measurements (heteromeric).
PubMed ID Year Study Type Assay Temperature Cell Type Result

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 G643S.
Neighbour residue Distance (Å) Observed variants
643 0 G643S,
642 4
644 4
641 5 P641L,
645 5
640 7 Q640L,
646 7 G646S
639 8
647 8
638 8
648 8 V648I,
637 9
649 9 D649N, D649G,
636 10
650 10
635 11 G635R, G635R,
651 11
634 11
652 11
633 12
653 12 F653Y,
632 13
654 13
631 13 P631R,
655 13
630 14 P630S, P630T,
656 14
629 14 G629S,
657 14 N657S,
628 15 G628S, G628D,
658 15 T658N,