rs199473664

Variant summary

Our verdict is Likely pathogenic. The variant received 6 ACMG points: 6P and 0B. PM1PM2PP2PP3

The NM_000238.4(KCNH2):​c.185G>A​(p.Arg62Gln) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000249 in 1,608,386 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★). Synonymous variant affecting the same amino acid position (i.e. R62R) has been classified as Likely benign.

Frequency

Genomes: 𝑓 0.000013 ( 0 hom., cov: 34)
Exomes 𝑓: 0.0000014 ( 0 hom. )

Consequence

KCNH2
NM_000238.4 missense

Scores

6
3
8

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:2O:1

Conservation

PhyloP100: 1.88

Publications

2 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_pathogenic. The variant received 6 ACMG points.

PM1
In a hotspot region, there are 16 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 21 uncertain in NM_000238.4
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.
PP3
MetaRNN computational evidence supports a deleterious effect, 0.836

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
KCNH2NM_000238.4 linkc.185G>A p.Arg62Gln missense_variant Exon 2 of 15 ENST00000262186.10 NP_000229.1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
KCNH2ENST00000262186.10 linkc.185G>A p.Arg62Gln missense_variant Exon 2 of 15 1 NM_000238.4 ENSP00000262186.5
KCNH2ENST00000713710.1 linkc.185G>A p.Arg62Gln missense_variant Exon 2 of 15 ENSP00000519013.1
KCNH2ENST00000532957.5 linkn.408G>A non_coding_transcript_exon_variant Exon 2 of 9 2
KCNH2ENST00000713700.1 linkn.143G>A non_coding_transcript_exon_variant Exon 2 of 9

Frequencies

GnomAD3 genomes
AF:
0.0000131
AC:
2
AN:
152248
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:
0.0000294
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.00000424
AC:
1
AN:
235930
AF XY:
0.00000776
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:
0.00000959
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.00000137
AC:
2
AN:
1456138
Hom.:
0
Cov.:
34
AF XY:
0.00000276
AC XY:
2
AN XY:
724174
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33336
American (AMR)
AF:
0.00
AC:
0
AN:
44320
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26010
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39412
South Asian (SAS)
AF:
0.00
AC:
0
AN:
85704
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
51958
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5490
European-Non Finnish (NFE)
AF:
0.00000180
AC:
2
AN:
1109880
Other (OTH)
AF:
0.00
AC:
0
AN:
60028
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.450
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance
GnomAD4 genome
AF:
0.0000131
AC:
2
AN:
152248
Hom.:
0
Cov.:
34
AF XY:
0.00
AC XY:
0
AN XY:
74374
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41464
American (AMR)
AF:
0.00
AC:
0
AN:
15292
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3472
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5192
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4838
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10630
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.0000294
AC:
2
AN:
68040
Other (OTH)
AF:
0.00
AC:
0
AN:
2092
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.625
Heterozygous variant carriers
0
0
1
1
2
2
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:
0.00000756

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:2Other:1
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Long QT syndrome Uncertain:2
Sep 27, 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. This sequence change replaces arginine, which is basic and polar, with glutamine, which is neutral and polar, at codon 62 of the KCNH2 protein (p.Arg62Gln). This variant is present in population databases (rs199473664, gnomAD 0.001%). This missense change has been observed in individual(s) with clinical features of KCNH2-related conditions (PMID: 18752142, 29881912). ClinVar contains an entry for this variant (Variation ID: 67298). Algorithms developed to predict the effect of missense changes on protein structure and function (SIFT, PolyPhen-2, Align-GVGD) all suggest that this variant is likely to be tolerated. Experimental studies have shown that this missense change affects KCNH2 function (PMID: 29881912).

Jun 09, 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 arginine with glutamine at codon 62 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 been reported in at least 2 individuals with suspected long QT syndrome (PMID: 18752142, 29881912). This variant has been identified in 1/235930 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.

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:18752142). 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
0.094
CardioboostArm
Benign
0.083
BayesDel_addAF
Pathogenic
0.30
D
BayesDel_noAF
Pathogenic
0.20
CADD
Pathogenic
27
DANN
Uncertain
0.98
DEOGEN2
Uncertain
0.69
D;D
Eigen
Benign
-0.29
Eigen_PC
Benign
-0.19
LIST_S2
Uncertain
0.93
D;D
M_CAP
Pathogenic
0.90
D
MetaRNN
Pathogenic
0.84
D;D
MetaSVM
Pathogenic
1.2
D
MutationAssessor
Benign
1.2
L;.
PhyloP100
1.9
PrimateAI
Pathogenic
0.82
D
PROVEAN
Benign
-1.2
N;.
Sift
Benign
0.35
T;.
Sift4G
Benign
0.28
T;T
Vest4
0.47
ClinPred
0.24
T
GERP RS
4.4
Varity_R
0.34
gMVP
0.94
Mutation Taster
=22/78
disease causing

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.010
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: rs199473664; hg19: chr7-150671921; API