7-150947684-G-T

Variant summary

Our verdict is Likely benign. The variant received -3 ACMG points: 1P and 4B. PP2BS2

The NM_000238.4(KCNH2):​c.2887C>A​(p.Pro963Thr) variant causes a missense change. The variant allele was found at a frequency of 0.0000206 in 1,601,002 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. P963R) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.000020 ( 0 hom., cov: 33)
Exomes 𝑓: 0.000021 ( 0 hom. )

Consequence

KCNH2
NM_000238.4 missense

Scores

3
7
9

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:5B:1O:1

Conservation

PhyloP100: 4.76

Publications

6 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 -3 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.
BS2
High AC in GnomAdExome4 at 30 AD gene.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
KCNH2NM_000238.4 linkc.2887C>A p.Pro963Thr missense_variant Exon 12 of 15 ENST00000262186.10 NP_000229.1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
KCNH2ENST00000262186.10 linkc.2887C>A p.Pro963Thr missense_variant Exon 12 of 15 1 NM_000238.4 ENSP00000262186.5

Frequencies

GnomAD3 genomes
AF:
0.0000197
AC:
3
AN:
152178
Hom.:
0
Cov.:
33
show subpopulations
Gnomad AFR
AF:
0.00
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:
0.0000441
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.00000915
AC:
2
AN:
218618
AF XY:
0.00000833
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.00
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.0000551
Gnomad NFE exome
AF:
0.0000104
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000207
AC:
30
AN:
1448824
Hom.:
0
Cov.:
36
AF XY:
0.0000236
AC XY:
17
AN XY:
719732
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33294
American (AMR)
AF:
0.00
AC:
0
AN:
43230
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
25866
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39176
South Asian (SAS)
AF:
0.00
AC:
0
AN:
84416
European-Finnish (FIN)
AF:
0.0000394
AC:
2
AN:
50786
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5638
European-Non Finnish (NFE)
AF:
0.0000253
AC:
28
AN:
1106620
Other (OTH)
AF:
0.00
AC:
0
AN:
59798
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.492
Heterozygous variant carriers
0
2
4
6
8
10
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:
0.0000197
AC:
3
AN:
152178
Hom.:
0
Cov.:
33
AF XY:
0.0000269
AC XY:
2
AN XY:
74338
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41458
American (AMR)
AF:
0.00
AC:
0
AN:
15288
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3470
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5178
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4834
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10620
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.0000441
AC:
3
AN:
68010
Other (OTH)
AF:
0.00
AC:
0
AN:
2092
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.492
Heterozygous variant carriers
0
1
1
2
2
3
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Genome 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
Alfa
AF:
0.00
Hom.:
0
Bravo
AF:
0.0000151
ExAC
AF:
0.00000836
AC:
1

ClinVar

Significance: Conflicting classifications of pathogenicity
Submissions summary: Uncertain:5Benign:1Other:1
Revision: criteria provided, conflicting classifications
LINK: link

Submissions by phenotype

Long QT syndrome Uncertain:2
Mar 05, 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 proline with threonine at codon 963 of the KCNH2 protein. Computational prediction is inconclusive regarding the impact of this variant on protein structure and function (internally defined REVEL score threshold 0.5 < inconclusive < 0.7, PMID: 27666373). Splice site prediction tools suggest that this variant may not impact RNA splicing. Functional studies have shown this variant has no detectable impact on membrane surface expression or biophysical gating properties (PMID: 29331839, 31493592). This variant has been reported in a few individuals affected with long QT syndrome (PMID: 19841300, 22949429, 28861002). This variant has also been reported in two related individuals affected with recurrent sudden infant death syndrome and in two other family members who had no cardiac phenotypes (PMID: 29331839). This variant has not been identified 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.

Jul 10, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces proline, which is neutral and non-polar, with threonine, which is neutral and polar, at codon 963 of the KCNH2 protein (p.Pro963Thr). 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 missense change has been observed in individual(s) with long QT syndrome and/or sudden infant death syndrome (PMID: 19841300, 29331839). ClinVar contains an entry for this variant (Variation ID: 67449). 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 disruptive. Experimental studies have shown that this missense change does not substantially affect KCNH2 function (PMID: 29331839, 31493592). 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:1
Aug 07, 2017
ARUP Laboratories, Molecular Genetics and Genomics, ARUP Laboratories
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The p.Pro963Thr variant (rs199473014) was reported in one patient in a cohort of ~400, and determined as one of C-terminal variants in KCNH2 with elevated allele frequency in Long-QT cases compared to controls (Kapa, 2009). Further analysis using a combination of prediction tools concluded this variant might be benign (Giudicessi, 2012). This variant is listed in the Genome Aggregation Database (gnomAD) with an overall population frequency of 0.0009 percent (identified on 2 out of 214,534 chromosomes). It is also reported in ClinVar (Variation ID: 67449) without any clinical significance. The proline at position 963 is moderately conserved and computational analyses of the effects of the p.Pro963Thr variant on protein structure and function provide conflicting results (SIFT: tolerated, MutationTaster: disease causing, PolyPhen-2: benign). Altogether, there is not enough evidence to classify the p.Pro963Thr variant with certainty.

Short QT syndrome type 1;C3150943:Long QT syndrome 2 Uncertain:1
Oct 11, 2021
Fulgent Genetics, Fulgent Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Cardiac arrhythmia Uncertain:1
May 25, 2023
Color Diagnostics, LLC DBA Color Health
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This missense variant replaces proline with threonine at codon 963 of the KCNH2 protein. Computational prediction is inconclusive regarding the impact of this variant on protein structure and function (internally defined REVEL score threshold 0.5 < inconclusive < 0.7, PMID: 27666373). Splice site prediction tools suggest that this variant may not impact RNA splicing. Functional studies have shown this variant has no detectable impact on membrane surface expression or biophysical gating properties (PMID: 29331839, 31493592). This variant has been reported in a few individuals affected with long QT syndrome (PMID: 19841300, 22949429, 28861002). This variant has also been reported in two related individuals affected with recurrent sudden infant death syndrome and in two other family members who had no cardiac phenotypes (PMID: 29331839). This variant has not been identified 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.

Cardiovascular phenotype Benign:1
Sep 16, 2021
Ambry Genetics
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This alteration is classified as likely benign based on a combination of the following: seen in unaffected individuals, population frequency, intact protein function, lack of segregation with disease, co-occurrence, RNA analysis, in silico models, amino acid conservation, lack of disease association in case-control studies, and/or the mechanism of disease or impacted region is inconsistent with a known cause of pathogenicity.

Congenital long QT syndrome Other:1
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 as associated with Long QT syndrome in the following publications (PMID:19841300). This is a literature report, and does not necessarily reflect the clinical interpretation of the Imperial College / Royal Brompton Cardiovascular Genetics laboratory.

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.066
CardioboostArm
Uncertain
0.39
BayesDel_addAF
Pathogenic
0.30
D
BayesDel_noAF
Pathogenic
0.19
CADD
Benign
22
DANN
Uncertain
1.0
DEOGEN2
Benign
0.0
.;T
Eigen
Benign
-0.21
Eigen_PC
Benign
-0.038
FATHMM_MKL
Uncertain
0.90
D
LIST_S2
Benign
0.84
T;T
M_CAP
Pathogenic
0.50
D
MetaRNN
Uncertain
0.73
D;D
MetaSVM
Uncertain
0.56
D
MutationAssessor
Benign
0.0
.;N
PhyloP100
4.8
PrimateAI
Uncertain
0.59
T
PROVEAN
Benign
-1.0
N;N
REVEL
Uncertain
0.54
Sift
Benign
0.39
T;T
Sift4G
Benign
0.19
T;T
Vest4
0.55
ClinPred
0.21
T
GERP RS
4.1
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
1.9
Varity_R
0.14
gMVP
0.69
Mutation Taster
=17/83
disease causing

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.060
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: rs199473014; hg19: chr7-150644772; COSMIC: COSV51225033; COSMIC: COSV51225033; API