KCNH2 Variant A527W

Summary of observed carriers, functional annotations, and structural context for KCNH2 A527W. Data combine curated literature, international cohorts, and gnomAD observations.

Estimated LQT2 penetrance

19%

1/10 effective observations

Total carriers

0

0 LQT2 · 0 unaffected

Functional studies

1

Publications with functional data

A527W has not been reported in gnomAD. This residue resides in a Hotspot region for LQT2.

We have tested the trafficking efficiency of this variant: 0% of WT with a standard error of 14%. 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 (%)
None None None None 46

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.

Functional data

Functional assay results from published electrophysiology studies. Steady state (S.S.) and peak tail current are relative % to wildtype (100% being no different from wildtype). V1/2 activation and inactivation are the voltages at which half of the maximal current is reached, in mV. Recovery from inactivation and deactivation time are ratios of characteristic time constants with wildtype. HM indicates homomeric channels, HT indicates heteromeric channels.

Homomeric channel data

Published electrophysiology measurements (homomeric).
PubMed ID Cell Type S.S Peak (%WT) Peak Tail IKr (%WT) V1/2 Act. V1/2 Inact. Recov. Inact. Deactivation (%WT)
16166152 Xeno 1.2 None None 1.0

Heteromeric channel data

Published electrophysiology measurements (heteromeric).
PubMed ID Cell Type S.S Peak (%WT) Peak Tail IKr (%WT) V1/2 Act. V1/2 Inact. Deactivation (%WT)
16166152 Xeno None None None

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 A527W.
Neighbour residue Distance (Å) Observed variants
527 0
526 4
528 5 R528W, R528X, R528P,
530 5
529 5
504 6 A504V,
503 6
531 7 R531W, R531Del, R531Q,
524 7
525 7 K525N, K525N,
506 8 I506V,
425 9
505 9 A505V,
421 9 T421fsX, T421M,
523 9
500 9 I500Del,
502 10 M502I, M502I, M502I,
508 10
507 10 P507S, P507L,
501 10 D501N, D501H, D501Y,
522 10 G522E,
532 11
426 11 P426H,
422 11 A422T,
533 11
460 11 D460fsX,
463 11 F463L, F463L, F463L,
429 12 A429P, A429V,
418 12
534 12 R534C,
499 12
428 13 S428fsX, S428X, S428L,
456 13 D456Y,
459 13
563 13 W563G, W563C, W563C, W563X
521 13
420 13 Y420C,
423 14
424 14
464 14 I464X,
498 14
417 14
430 15
419 15