7-150951463-C-T

Variant summary

Our verdict is Likely benign. The variant received -1 ACMG points: 3P and 4B. PM1PP2BS2

The NM_000238.4(KCNH2):​c.1930G>A​(p.Val644Ile) variant causes a missense change. The variant allele was found at a frequency of 0.00000929 in 1,613,992 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. V644L) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 34)
Exomes 𝑓: 0.0000096 ( 0 hom. )

Consequence

KCNH2
NM_000238.4 missense

Scores

4
8
8

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:4

Conservation

PhyloP100: 6.02

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: Likely_benign. The variant received -1 ACMG points.

PM1
In a hotspot region, there are 13 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 24 uncertain in NM_000238.4
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 14 AD gene.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
KCNH2NM_000238.4 linkc.1930G>A p.Val644Ile missense_variant Exon 7 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.1930G>A p.Val644Ile missense_variant Exon 7 of 15 1 NM_000238.4 ENSP00000262186.5 Q12809-1

Frequencies

GnomAD3 genomes
AF:
0.00000657
AC:
1
AN:
152208
Hom.:
0
Cov.:
34
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:
0.0000147
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.0000159
AC:
4
AN:
251402
AF XY:
0.0000294
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.00
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.0000544
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.00
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.00000958
AC:
14
AN:
1461784
Hom.:
0
Cov.:
34
AF XY:
0.0000138
AC XY:
10
AN XY:
727188
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33480
American (AMR)
AF:
0.00
AC:
0
AN:
44722
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26136
East Asian (EAS)
AF:
0.0000252
AC:
1
AN:
39700
South Asian (SAS)
AF:
0.0000927
AC:
8
AN:
86258
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53360
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5734
European-Non Finnish (NFE)
AF:
0.00000450
AC:
5
AN:
1112008
Other (OTH)
AF:
0.00
AC:
0
AN:
60386
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.450
Heterozygous variant carriers
0
1
3
4
6
7
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:
0.00000657
AC:
1
AN:
152208
Hom.:
0
Cov.:
34
AF XY:
0.0000134
AC XY:
1
AN XY:
74358
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41466
American (AMR)
AF:
0.00
AC:
0
AN:
15290
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:
4830
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:
0.0000147
AC:
1
AN:
68034
Other (OTH)
AF:
0.00
AC:
0
AN:
2092
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.525
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance
Alfa
AF:
0.00
Hom.:
0
ExAC
AF:
0.0000330
AC:
4

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:4
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

not provided Uncertain:1
Sep 07, 2021
AiLife Diagnostics, AiLife Diagnostics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Long QT syndrome Uncertain:1
Jan 22, 2023
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: "Probably Damaging"; Align-GVGD: "Class C0"). ClinVar contains an entry for this variant (Variation ID: 1009718). This variant has not been reported in the literature in individuals affected with KCNH2-related conditions. This variant is present in population databases (rs199472972, gnomAD 0.01%). This sequence change replaces valine, which is neutral and non-polar, with isoleucine, which is neutral and non-polar, at codon 644 of the KCNH2 protein (p.Val644Ile). -

Cardiovascular phenotype Uncertain:1
Feb 28, 2025
Ambry Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The p.V644I variant (also known as c.1930G>A), located in coding exon 7 of the KCNH2 gene, results from a G to A substitution at nucleotide position 1930. The valine at codon 644 is replaced by isoleucine, an amino acid with highly similar properties. This amino acid position is well conserved in available vertebrate species. In addition, this alteration is predicted to be deleterious by in silico analysis. Based on the available evidence, the clinical significance of this variant remains unclear. -

Cardiac arrhythmia Uncertain:1
May 31, 2023
Color Diagnostics, LLC DBA Color Health
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This missense variant replaces valine with isoleucine at codon 644 of the KCNH2 protein. Computational prediction suggests that this variant may have deleterious impact on protein structure and function (internally defined REVEL score threshold >= 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 4/251402 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
0.17
CardioboostArm
Benign
0.019
BayesDel_addAF
Uncertain
0.15
D
BayesDel_noAF
Pathogenic
0.18
CADD
Pathogenic
29
DANN
Uncertain
1.0
DEOGEN2
Uncertain
0.74
.;D;D
Eigen
Benign
0.18
Eigen_PC
Uncertain
0.23
FATHMM_MKL
Uncertain
0.94
D
LIST_S2
Uncertain
0.89
D;D;D
M_CAP
Pathogenic
0.65
D
MetaRNN
Uncertain
0.69
D;D;D
MetaSVM
Pathogenic
1.0
D
MutationAssessor
Benign
1.6
.;L;.
PhyloP100
6.0
PrimateAI
Uncertain
0.72
T
PROVEAN
Benign
-0.84
N;N;.
REVEL
Pathogenic
0.74
Sift
Benign
0.20
T;T;.
Sift4G
Benign
0.20
T;T;T
Polyphen
0.18
B;P;.
Vest4
0.58
MutPred
0.76
.;Loss of catalytic residue at V644 (P = 0.0631);.;
MVP
0.85
MPC
2.0
ClinPred
0.81
D
GERP RS
3.3
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
2.1
Varity_R
0.19
gMVP
0.91
Mutation Taster
=46/54
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: rs199472972; hg19: chr7-150648551; COSMIC: COSV51231983; API