KCNQ1 Variant S546L

Summary of observed carriers, functional annotations, and structural context for KCNQ1 S546L. Data combine curated literature, international cohorts, and gnomAD observations.

Estimated LQT1 penetrance

67%

12/19 effective observations

Total carriers

9

9 LQT1 · 0 unaffected

Functional studies

2

Publications with functional data

S546L has not been reported in gnomAD. This residue resides in a Hotspot region for LQT1.

Variant features alone are equivalent to phenotyping 3 individuals with LQT1 and 7 unaffected individuals.

In silico predictors

Variant-level computational predictors.
PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density LQT1 (%)
-4.95 0.987 -2 0.94 50

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
32893267 2020 7 None 7 None
24363352 2014 1 None None None
23631430 2013 2 None None None
22949429 2012 2 None 2 None
21956039 2011 1 None 1 None
21131640 2011 1 None 1 None
19841300 2009 2 None 2 None
19808498 2009 1 None 1 None
19716085 2009 4 None 4 None
Literature, cohort, and gnomAD 9 0 9
Variant features alone 15 7 3

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 S546L.
Neighbour residue Distance (Å) Observed variants
545 11
549 12
548 13 G548S,
541 13 V541I,
546 13 S546L, S546W
544 13 Q544E,
542 13
552 14 L552F,
524 15 V524G,