chr7-150947800-C-A

Variant summary

Our verdict is Uncertain significance. The variant received 3 ACMG points: 3P and 0B. PM2PP2

The NM_000238.4(KCNH2):​c.2771G>T​(p.Gly924Val) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000218 in 1,378,290 control chromosomes in the GnomAD database, with no homozygous occurrence. 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. G924A) has been classified as Uncertain significance.

Frequency

Genomes: not found (cov: 33)
Exomes 𝑓: 0.0000022 ( 0 hom. )

Consequence

KCNH2
NM_000238.4 missense

Scores

4
4
12

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:2

Conservation

PhyloP100: 1.01

Publications

14 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: Uncertain_significance. The variant received 3 ACMG points.

PM2
Very rare variant in population databases, with high coverage;
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.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
KCNH2NM_000238.4 linkc.2771G>T p.Gly924Val missense_variant Exon 12 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.2771G>T p.Gly924Val missense_variant Exon 12 of 15 1 NM_000238.4 ENSP00000262186.5 Q12809-1

Frequencies

GnomAD3 genomes
Cov.:
33
GnomAD2 exomes
AF:
0.00000786
AC:
1
AN:
127254
AF XY:
0.00
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:
0.00
Gnomad NFE exome
AF:
0.0000213
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.00000218
AC:
3
AN:
1378290
Hom.:
0
Cov.:
36
AF XY:
0.00000147
AC XY:
1
AN XY:
679366
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
31396
American (AMR)
AF:
0.00
AC:
0
AN:
35306
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
24766
East Asian (EAS)
AF:
0.00
AC:
0
AN:
35616
South Asian (SAS)
AF:
0.00
AC:
0
AN:
78220
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
35868
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
4108
European-Non Finnish (NFE)
AF:
0.00000279
AC:
3
AN:
1075592
Other (OTH)
AF:
0.00
AC:
0
AN:
57418
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.592
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

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
Cov.:
33

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:2
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Long QT syndrome Uncertain:2
May 30, 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 glycine with valine at codon 924 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). To our knowledge, functional studies have not been reported for this variant. This variant has not been reported in individuals affected with KCNH2-related disorders in the literature. This variant has been identified in 1/127254 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. -

Apr 08, 2022
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

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. Algorithms developed to predict the effect of missense changes on protein structure and function are either unavailable or do not agree on the potential impact of this missense change (SIFT: "Tolerated"; PolyPhen-2: "Possibly Damaging"; Align-GVGD: "Class C0"). This variant is also known as G584V (c.1751G>T). This missense change has been observed in individual(s) with KCNH2-related conditions (PMID: 18752142). 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 sequence change replaces glycine, which is neutral and non-polar, with valine, which is neutral and non-polar, at codon 924 of the KCNH2 protein (p.Gly924Val). -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.093
CardioboostArm
Benign
0.0019
BayesDel_addAF
Pathogenic
0.34
D
BayesDel_noAF
Pathogenic
0.24
CADD
Benign
18
DANN
Uncertain
1.0
DEOGEN2
Benign
0.34
.;T
Eigen
Benign
0.12
Eigen_PC
Benign
0.10
FATHMM_MKL
Benign
0.49
N
LIST_S2
Benign
0.85
D;D
M_CAP
Pathogenic
0.82
D
MetaRNN
Uncertain
0.51
D;D
MetaSVM
Pathogenic
0.92
D
MutationAssessor
Benign
1.1
.;L
PhyloP100
1.0
PrimateAI
Uncertain
0.66
T
PROVEAN
Benign
-1.3
N;N
REVEL
Uncertain
0.61
Sift
Benign
0.11
T;T
Sift4G
Benign
0.33
T;T
Polyphen
0.98
D;D
Vest4
0.35
MutPred
0.38
.;Loss of relative solvent accessibility (P = 0.0186);
MVP
0.97
MPC
0.70
ClinPred
0.73
D
GERP RS
5.0
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
1.7
Varity_R
0.23
gMVP
0.60
Mutation Taster
=7/93
disease causing

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: rs199473009; hg19: chr7-150644888; API