rs140743924

Variant summary

Our verdict is Likely benign. The variant received -4 ACMG points: 1P and 5B. PP2BP4BS2

The NM_000238.4(KCNH2):​c.2624C>T​(p.Thr875Met) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000224 in 1,565,862 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. T875P) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.000027 ( 0 hom., cov: 31)
Exomes 𝑓: 0.000022 ( 0 hom. )

Consequence

KCNH2
NM_000238.4 missense

Scores

2
4
14

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:5O:1

Conservation

PhyloP100: 2.30

Publications

5 publications found
Variant links:
Genes affected
KCNH2 (HGNC:6251): (potassium voltage-gated channel subfamily H member 2) This gene encodes a component of a voltage-activated potassium channel found in cardiac muscle, nerve cells, and microglia. Four copies of this protein interact with one copy of the KCNE2 protein to form a functional potassium channel. Mutations in this gene can cause long QT syndrome type 2 (LQT2). Transcript variants encoding distinct isoforms have been identified. [provided by RefSeq, May 2022]
KCNH2 Gene-Disease associations (from GenCC):
  • long QT syndrome
    Inheritance: AD Classification: DEFINITIVE Submitted by: ClinGen
  • long QT syndrome 2
    Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: Labcorp Genetics (formerly Invitae), Ambry Genetics, G2P
  • short QT syndrome
    Inheritance: AD Classification: DEFINITIVE, SUPPORTIVE Submitted by: Orphanet, ClinGen
  • short QT syndrome type 1
    Inheritance: AD Classification: DEFINITIVE, STRONG, MODERATE Submitted by: Labcorp Genetics (formerly Invitae), G2P, Ambry Genetics
  • Brugada syndrome
    Inheritance: AD Classification: MODERATE, NO_KNOWN Submitted by: ClinGen, Genomics England PanelApp

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Likely_benign. The variant received -4 ACMG points.

PP2
Missense variant in the gene, where a lot of missense mutations are associated with disease in ClinVar. The gene has 158 curated pathogenic missense variants (we use a threshold of 10). The gene has 38 curated benign missense variants. Gene score misZ: 3.3724 (above the threshold of 3.09). Trascript score misZ: 2.4846 (below the threshold of 3.09). GenCC associations: The gene is linked to long QT syndrome 2, Brugada syndrome, short QT syndrome type 1, short QT syndrome, long QT syndrome.
BP4
Computational evidence support a benign effect (MetaRNN=0.2757076).
BS2
High AC in GnomAdExome4 at 31 AD gene.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
KCNH2NM_000238.4 linkc.2624C>T p.Thr875Met missense_variant Exon 11 of 15 ENST00000262186.10 NP_000229.1 Q12809-1Q15BH2A0A090N8Q0

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
KCNH2ENST00000262186.10 linkc.2624C>T p.Thr875Met missense_variant Exon 11 of 15 1 NM_000238.4 ENSP00000262186.5 Q12809-1

Frequencies

GnomAD3 genomes
AF:
0.0000269
AC:
4
AN:
148564
Hom.:
0
Cov.:
31
show subpopulations
Gnomad AFR
AF:
0.0000247
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.00
Gnomad ASJ
AF:
0.00
Gnomad EAS
AF:
0.00
Gnomad SAS
AF:
0.00
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.0000446
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.0000120
AC:
3
AN:
250496
AF XY:
0.00000738
show subpopulations
Gnomad AFR exome
AF:
0.0000617
Gnomad AMR exome
AF:
0.00
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.00000883
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000219
AC:
31
AN:
1417298
Hom.:
0
Cov.:
37
AF XY:
0.0000241
AC XY:
17
AN XY:
704740
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
31928
American (AMR)
AF:
0.00
AC:
0
AN:
43286
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
24414
East Asian (EAS)
AF:
0.0000276
AC:
1
AN:
36262
South Asian (SAS)
AF:
0.0000582
AC:
5
AN:
85850
European-Finnish (FIN)
AF:
0.0000202
AC:
1
AN:
49578
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5504
European-Non Finnish (NFE)
AF:
0.0000203
AC:
22
AN:
1083132
Other (OTH)
AF:
0.0000349
AC:
2
AN:
57344
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.475
Heterozygous variant carriers
0
3
6
8
11
14
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
2
4
6
8
10
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
GnomAD4 genome
AF:
0.0000269
AC:
4
AN:
148564
Hom.:
0
Cov.:
31
AF XY:
0.0000276
AC XY:
2
AN XY:
72354
show subpopulations
African (AFR)
AF:
0.0000247
AC:
1
AN:
40466
American (AMR)
AF:
0.00
AC:
0
AN:
14872
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3444
East Asian (EAS)
AF:
0.00
AC:
0
AN:
4766
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4456
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
9954
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
314
European-Non Finnish (NFE)
AF:
0.0000446
AC:
3
AN:
67328
Other (OTH)
AF:
0.00
AC:
0
AN:
2072
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.475
Heterozygous variant carriers
0
1
1
2
2
3
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance
Alfa
AF:
0.0000319
Hom.:
0
ESP6500AA
AF:
0.000227
AC:
1
ESP6500EA
AF:
0.00
AC:
0
ExAC
AF:
0.0000330
AC:
4
Asia WGS
AF:
0.000866
AC:
3
AN:
3478
EpiCase
AF:
0.0000545
EpiControl
AF:
0.00

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:5Other:1
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Long QT syndrome Uncertain:2
Jul 10, 2024
All of Us Research Program, National Institutes of Health
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This missense variant replaces threonine with methionine at codon 875 of the KCNH2 protein. Computational prediction suggests that this variant may not impact protein structure and function (internally defined REVEL score threshold <= 0.5, PMID: 27666373). To our knowledge, functional studies have not been reported for this variant. This variant has not been reported in individuals affected with cardiovascular disorders in the literature. This variant has been identified in 3/250496 chromosomes in the general population by the Genome Aggregation Database (gnomAD). The available evidence is insufficient to determine the role of this variant in disease conclusively. Therefore, this variant is classified as a Variant of Uncertain Significance. -

Nov 13, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces threonine, which is neutral and polar, with methionine, which is neutral and non-polar, at codon 875 of the KCNH2 protein (p.Thr875Met). The frequency data for this variant in the population databases is considered unreliable, as metrics indicate poor data quality at this position in the gnomAD database. This variant has not been reported in the literature in individuals affected with KCNH2-related conditions. ClinVar contains an entry for this variant (Variation ID: 67420). An algorithm developed to predict the effect of missense changes on protein structure and function (PolyPhen-2) suggests that this variant is likely to be tolerated. In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. -

not provided Uncertain:1Other:1
Dec 23, 2024
GeneDx
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Not observed at significant frequency in large population cohorts (gnomAD); In silico analysis indicates that this missense variant does not alter protein structure/function; Observed among a cohort of healthy individuals screened for genetic variations in long QT syndrome (LQTS)-associated genes (PMID: 16487223); This variant is associated with the following publications: (PMID: 16487223, 22947121) -

-
Cardiovascular Biomedical Research Unit, Royal Brompton & Harefield NHS Foundation Trust
Significance:not provided
Review Status:no classification provided
Collection Method:literature only

This variant has been reported in the following publications (PMID:16487223). -

Cardiovascular phenotype Uncertain:1
Mar 18, 2020
Ambry Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The c.2624C>T (p.T875M) alteration is located in exon 11 (coding exon 11) of the KCNH2 gene. This alteration results from a C to T substitution at nucleotide position 2624, causing the threonine (T) at amino acid position 875 to be replaced by a methionine (M). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

Cardiac arrhythmia Uncertain:1
Jun 13, 2024
Color Diagnostics, LLC DBA Color Health
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This missense variant replaces threonine with methionine at codon 875 of the KCNH2 protein. Computational prediction suggests that this variant may not impact protein structure and function (internally defined REVEL score threshold <= 0.5, PMID: 27666373). To our knowledge, functional studies have not been reported for this variant. This variant has not been reported in individuals affected with cardiovascular disorders in the literature. This variant has been identified in 3/250496 chromosomes in the general population by the Genome Aggregation Database (gnomAD). The available evidence is insufficient to determine the role of this variant in disease conclusively. Therefore, this variant is classified as a Variant of Uncertain Significance. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.091
CardioboostArm
Benign
0.0000017
BayesDel_addAF
Uncertain
0.14
D
BayesDel_noAF
Uncertain
-0.030
CADD
Benign
22
DANN
Uncertain
0.99
DEOGEN2
Benign
0.41
.;T
Eigen
Benign
-0.32
Eigen_PC
Benign
-0.35
FATHMM_MKL
Benign
0.44
N
LIST_S2
Benign
0.54
T;T
M_CAP
Pathogenic
0.69
D
MetaRNN
Benign
0.28
T;T
MetaSVM
Pathogenic
0.87
D
MutationAssessor
Benign
0.69
.;N
PhyloP100
2.3
PrimateAI
Benign
0.39
T
PROVEAN
Benign
-1.3
N;N
REVEL
Uncertain
0.42
Sift
Benign
0.13
T;T
Sift4G
Benign
0.098
T;T
Polyphen
1.0
D;B
Vest4
0.24
MVP
0.84
MPC
0.24
ClinPred
0.076
T
GERP RS
4.1
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
1.3
Varity_R
0.024
gMVP
0.58
Mutation Taster
=87/13
polymorphism

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.0
Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

Other links and lift over

dbSNP: rs140743924; hg19: chr7-150645600; API