KCNQ1 Variant Q234H

Summary of observed carriers, functional annotations, and structural context for KCNQ1 Q234H. Data combine curated literature, international cohorts, and gnomAD observations.

Estimated LQT1 penetrance

25%

2/11 effective observations

Total carriers

1

0 LQT1 · unaffected

Functional studies

0

Publications with functional data

Q234H is present in 1 alleles in gnomAD. This residue resides in a Mild_Hotspot region for LQT1.

Variant features alone are equivalent to phenotyping 2 individuals with LQT1 and 8 unaffected individuals.

In silico predictors

Variant-level computational predictors.
PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density LQT1 (%)
-4.81 0.981 -3 0.929 29

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 0 –
Variant features alone – 15 8 2 –

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