KCNH2 Variant Q335X
Summary of observed carriers, functional annotations, and structural context for KCNH2 Q335X. Data combine curated literature, international cohorts, and gnomAD observations.
Estimated LQT2 penetrance
%
NA/NA effective observations
Total carriers
3
1 LQT2 · 2 unaffected
Functional studies
0
Publications with functional data
We have tested the trafficking efficiency of this variant: 0% of WT with a standard error of 0%. In our analysis we used SE < 20% as 'high quality'. Approximately below 50% of WT is considered PS3 moderate and below 30% is PS3 strong.
In silico predictors
| PROVEAN | PolyPhen-2 | BLAST-PSSM | REVEL | Penetrance Density LQT2 (%) |
|---|---|---|---|---|
| None | None | None | None |
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 | LQT2 | Other Disease |
|---|---|---|---|---|---|
| Japan Cohort | 2020 | 3 | 2 | 1 | |
| Literature, cohort, and gnomAD | – | 3 | 2 | 1 | – |
| Variant features alone | – | 10 | NA | NA | – |
Totals may differ from individual publications due to duplicate patients removed during curation.