KCNQ1 Variant I574V

Summary of observed carriers, functional annotations, and structural context for KCNQ1 I574V. Data combine curated literature, international cohorts, and gnomAD observations.

Estimated LQT1 penetrance

16%

1/11 effective observations

Total carriers

1

0 LQT1 · 1 unaffected

Functional studies

1

Publications with functional data

I574V is present in 1 alleles in gnomAD. This residue resides in a Mild_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 (%)
-0.42 0.001 0 0.596 19

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 – 1 1 0 –
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 I574V.
Neighbour residue Distance (Å) Observed variants
574 0 I574V,
573 4 F573L, F573L, F573L,
575 4
572 5
576 5 V576I,
571 7 S571L, S571P,
577 7
570 8 P570L,
578 8 E578K, E578V,
569 8 K569E,
579 8
568 9 G568R, G568R, G568E,
580 9 S580G, S580N,
567 10 I567T, I567S,
581 10
566 11 S566F, S566Y, S566P,
582 11
565 11
583 11 R583H, R583C, R583G,
564 12 D564H, D564N,
584 12 G584S,
563 13
585 13 S585N
562 13 R562M, R562S, R562S,
586 13 N586D,
561 14
587 14 T587M, T587R,
560 14
588 14 I588F,
559 15 L559P,
589 15 G589D, G589S,