KCNQ1 Variant E261G

Summary of observed carriers, functional annotations, and structural context for KCNQ1 E261G. Data combine curated literature, international cohorts, and gnomAD observations.

Estimated LQT1 penetrance

70%

7/11 effective observations

Total carriers

1

1 LQT1 · 0 unaffected

Functional studies

0

Publications with functional data

E261G 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 (%)
-6.8 0.998 -3 0.935 74

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
33614747 2021 1 None 1 None
Literature, cohort, and gnomAD – 1 0 1 –
Variant features alone – 15 4 6 –

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

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 E261G.
Neighbour residue Distance (Å) Observed variants
247 9 T247I,
254 10 V254M, V254L, V254L,
250 10 L250H, L250P,
251 11 L251P, L251Q,
246 11
255 12
253 12 S253A, S253P,
257 12 I257V,
267 12 Y267C
252 12 G252R,
248 13 W248C, W248C, W248R, W248R,
269 14 G269D, G269S, G269del,
245 14 G245V,
256 14
242 14 D242N, D242Y,
351 14 F351L, F351L, F351L, F351S,
338 15 S338F,
355 15
339 15 F339del, F339S,