KCNH2 Variant C445S

Summary of observed carriers, functional annotations, and structural context for KCNH2 C445S. Data combine curated literature, international cohorts, and gnomAD observations.

Estimated LQT2 penetrance

18%

1/10 effective observations

Total carriers

0

0 LQT2 · 0 unaffected

Functional studies

0

Publications with functional data

C445S has not been reported in gnomAD. This residue resides in a Mild_Hotspot region for LQT2.

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.

Variant features alone are equivalent to phenotyping 1 individuals with LQT2 and 9 unaffected individuals.

In silico predictors

Variant-level computational predictors.
PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density LQT2 (%)
-8.101 0.23 -1 0.707 36

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 LQT2 Other Disease
Literature, cohort, and gnomAD 0 0 0
Variant features alone 10 9 1

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. Note that some residues appear multiple times at different distances since the functional KV11.1 channel (protein product of KCNH2/hERG) is a homotetramer and occasionally the same residue from multiple subunits is present within the 15Å window.

Previously observed variants near C445S.
Neighbour residue Distance (Å) Observed variants
445 0
444 4 E444K, E444D, E444D,
446 4
443 5 T443fsX, T443N,
447 5 Y447X,
442 7
448 7 A448T, A448S,
441 8 P441R, P441L,
449 8
440 8 P440L,
450 8
439 9
451 9 P451L,
438 10 E438K, E438X,
452 10
437 11
453 11
436 11 T436M,
454 11
435 12 E435G, E435X,
455 12
434 13
456 13 D456Y,
433 13
457 13 L457P,
432 14
458 14
431 14 F431L, F431L, F431L,
459 14
430 15
460 15 D460fsX,