KCNQ1 Variant G493W

Summary of observed carriers, functional annotations, and structural context for KCNQ1 G493W. Data combine curated literature, international cohorts, and gnomAD observations.

Estimated LQT1 penetrance

11%

1/10 effective observations

Total carriers

0 LQT1 · 0 unaffected

Functional studies

Publications with functional data

G493W has not been reported 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 (%)
-2.26	0.774	-4	0.815	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	–	0	0	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 G493W.
Neighbour residue	Distance (Å)	Observed variants
493	0	G493A,
492	4	L492ins,
494	4
491	5
495	5	T495S, T495S, T495A
490	7
496	7
489	8
497	8	L497P,
488	8	D488E, D488E,
498	8
487	9	E487K,
499	9	P499S,
486	10	A486T,
500	10	I500L, I500V,
485	11	F485S,
501	11	T501A,
484	11
502	11
483	12
503	12
482	13	T482N, T482A, T482S, T482S,
504	13
481	13
505	13	Q505R,
480	14	M480T,
506	14
479	14	F479L, F479L, F479L,
507	14	R507Q, R507W,
478	15	H478Y,
508	15	E508G,