KCNQ1 Variant D426V

Summary of observed carriers, functional annotations, and structural context for KCNQ1 D426V. Data combine curated literature, international cohorts, and gnomAD observations.

Estimated LQT1 penetrance

13%

1/10 effective observations

Total carriers

0 LQT1 · 0 unaffected

Functional studies

Publications with functional data

D426V 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 (%)
-2.73	0.049	-3	0.683	5

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 D426V.
Neighbour residue	Distance (Å)	Observed variants
426	0
425	4	L425V,
427	4
424	5	K424T,
428	5	D428G,
423	7
429	7	N429S,
422	8	K422T, K422R,
430	8
421	8	K421N, K421N,
431	8	V431L, V431L,
420	9	K420E, K420N, K420N,
432	9	T432I, T432A
419	10
433	10	P433A,
418	11	V418I,
434	11	G434R, G434R,
417	11	V417M,
435	11
416	12	V416M,
436	12
415	13
437	13	M437V,
414	13
438	13
413	14	K413R,
439	14
412	14	P412S,
440	14
411	15
441	15	P441S,