KCNQ1 Variant I257V
Summary of observed carriers, functional annotations, and structural context for KCNQ1 I257V. Data combine curated literature, international cohorts, and gnomAD observations.
Estimated LQT1 penetrance
59%
6/11 effective observations
Total carriers
1
0 LQT1 · 1 unaffected
Functional studies
0
Publications with functional data
Variant features alone are equivalent to phenotyping 6 individuals with LQT1 and 4 unaffected individuals.
In silico predictors
| PROVEAN | PolyPhen-2 | BLAST-PSSM | REVEL | Penetrance Density LQT1 (%) |
|---|---|---|---|---|
| -0.73 | 0.507 | -2 | 0.752 | 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
| Source | Year | Carriers | Unaffected | LQT1 | Other Disease |
|---|---|---|---|---|---|
| Literature, cohort, and gnomAD | – | 1 | 1 | 0 | – |
| 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.
| Neighbour residue | Distance (Å) | Observed variants |
|---|---|---|
| 256 | 5 | |
| 354 | 11 | |
| 351 | 11 | F351L, F351L, F351L, F351S, |
| 358 | 11 | K358T, |
| 359 | 11 | Q359del, |
| 261 | 12 | E261K, E261D, E261D, E261G, E261Q, |
| 357 | 12 | Q357H, Q357H, |
| 260 | 13 | |
| 250 | 13 | L250H, L250P, |
| 262 | 14 | L262P, L262R, L262V, |
| 253 | 15 | S253A, S253P |
| 342 | 15 | L342F, L342P, |
| 534 | 15 | |
| 251 | 15 | L251P, L251Q, |