KCNH2 Variant L532P

Summary of observed carriers, functional annotations, and structural context for KCNH2 L532P. Data combine curated literature, international cohorts, and gnomAD observations.

Estimated LQT2 penetrance

20%

1/10 effective observations

Total carriers

0

0 LQT2 · 0 unaffected

Functional studies

1

Publications with functional data

L532P has not been reported in gnomAD. This residue resides in a Hotspot region for LQT2.

We have tested the trafficking efficiency of this variant: 23% of WT with a standard error of 11%. 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 (%)
-6.709 0.94 -3 0.959 70

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)
21777565 HEK293 0 35.8 31.6 None None

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)
21777565 HEK293 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 L532P.
Neighbour residue Distance (Å) Observed variants
532 0
533 5
535 5 V535M,
418 6
529 6
530 7
534 7 R534C,
531 7 R531W, R531Del, R531Q,
536 7 A536X,
422 8 A422T,
421 8 T421fsX, T421M,
419 8
415 9
537 10 R537W,
414 10 I414fsX,
559 10 L559F, L559H,
538 10
501 10 D501N, D501H, D501Y,
417 10
563 10 W563G, W563C, W563C, W563X
556 10
500 10 I500Del,
527 11
463 11 F463L, F463L, F463L,
504 11 A504V,
539 11
528 11 R528W, R528X, R528P,
552 11 L552S,
542 11
555 11
423 11
425 12
497 12 W497L, W497X,
416 12
420 12 Y420C,
526 12
560 12 I560fsX, I560M,
411 13
503 13
426 13 P426H,
466 13 D466E, D466E,
558 14 A558P, A558E, A558V,
459 14
562 14 H562P, H562R, H562Q, H562Q,
502 14 M502I, M502I, M502I,
553 14 L553V,
413 14 L413P,
412 14 W412X,
424 14
505 14 A505V,
551 14 F551L, F551L, F551L,
540 15 D540fsX,
460 15 D460fsX,
499 15