KCNQ1 Variant C642Y

Summary of observed carriers, functional annotations, and structural context for KCNQ1 C642Y. Data combine curated literature, international cohorts, and gnomAD observations.

Estimated LQT1 penetrance

0/10 effective observations

Total carriers

0 LQT1 · 0 unaffected

Functional studies

Publications with functional data

C642Y has not been reported in gnomAD. This residue resides in a Non_Hotspot region for LQT1.

Variant features alone are equivalent to phenotyping 0 individuals with LQT1 and 10 unaffected individuals.

In silico predictors

Variant-level computational predictors.
PROVEAN	PolyPhen-2	BLAST-PSSM	REVEL	Penetrance Density LQT1 (%)
-0.84	0.044	2	0.638	1

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	10	0	–

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 C642Y.
Neighbour residue	Distance (Å)	Observed variants
642	0
641	4	P641L,
643	4	G643S,
640	5	Q640L,
644	5
639	7
645	7
638	8
646	8	G646S
637	8
647	8
636	9
648	9	V648I,
635	10	G635R, G635R,
649	10	D649N, D649G,
634	11
650	11
633	11
651	11
632	12
652	12
631	13	P631R,
653	13	F653Y,
630	13	P630S, P630T,
654	13
629	14	G629S,
655	14
628	14	G628S, G628D,
656	14
627	15
657	15	N657S,