KCNQ1 Variant Q357H

Summary of observed carriers, functional annotations, and structural context for KCNQ1 Q357H. Data combine curated literature, international cohorts, and gnomAD observations.

Estimated LQT1 penetrance

74%

9/13 effective observations

Total carriers

3

3 LQT1 · unaffected

Functional studies

0

Publications with functional data

Q357H has not been reported in gnomAD. This residue resides in a Hotspot region for LQT1.

Variant features alone are equivalent to phenotyping 6 individuals with LQT1 and 4 unaffected individuals.

In silico predictors

Variant-level computational predictors.
PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density LQT1 (%)
-4.22 0.954 0 0.861 73

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
19490272 2009 3 None 3 None
17470695 2007 3 None 3 None
14678125 2003 3 None 3 None
Literature, cohort, and gnomAD – 3 3 –
Variant features alone – 15 4 6 –

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