KCNQ1 Variant V648I

Summary of observed carriers, functional annotations, and structural context for KCNQ1 V648I. Data combine curated literature, international cohorts, and gnomAD observations.

Estimated LQT1 penetrance

2%

9/609 effective observations

Total carriers

599

7 LQT1 · unaffected

Functional studies

0

Publications with functional data

V648I is present in 484 alleles in gnomAD. This residue resides in a Non_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 (%)
0

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
29197658 2018 7 None 7 None
22949429 2012 9 9 None None
19841300 2009 9 9 None None
Literature, cohort, and gnomAD – 599 7 –
Variant features alone – 15 8 2 –

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