rs786205422

Variant summary

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

The NM_000238.4(KCNH2):​c.3394C>G​(p.Pro1132Ala) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000016 in 1,563,778 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. P1132S) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.000013 ( 0 hom., cov: 33)
Exomes 𝑓: 0.000016 ( 0 hom. )

Consequence

KCNH2
NM_000238.4 missense

Scores

2
9
9

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:7

Conservation

PhyloP100: 2.19

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_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=0.27354348).
BS2
High AC in GnomAdExome4 at 23 AD gene.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
KCNH2NM_000238.4 linkc.3394C>G p.Pro1132Ala missense_variant Exon 15 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.3394C>G p.Pro1132Ala missense_variant Exon 15 of 15 1 NM_000238.4 ENSP00000262186.5 Q12809-1

Frequencies

GnomAD3 genomes
AF:
0.0000131
AC:
2
AN:
152162
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:
0.000386
Gnomad SAS
AF:
0.00
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.00
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.0000181
AC:
3
AN:
165828
AF XY:
0.0000112
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.0000381
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.0000798
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.00
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000163
AC:
23
AN:
1411616
Hom.:
0
Cov.:
31
AF XY:
0.0000100
AC XY:
7
AN XY:
697548
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
32214
American (AMR)
AF:
0.0000266
AC:
1
AN:
37532
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
25300
East Asian (EAS)
AF:
0.000109
AC:
4
AN:
36764
South Asian (SAS)
AF:
0.00
AC:
0
AN:
80170
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
49230
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5698
European-Non Finnish (NFE)
AF:
9.21e-7
AC:
1
AN:
1086224
Other (OTH)
AF:
0.000291
AC:
17
AN:
58484
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.479
Heterozygous variant carriers
0
2
3
5
6
8
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:
0.0000131
AC:
2
AN:
152162
Hom.:
0
Cov.:
33
AF XY:
0.00
AC XY:
0
AN XY:
74328
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41438
American (AMR)
AF:
0.00
AC:
0
AN:
15284
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3472
East Asian (EAS)
AF:
0.000386
AC:
2
AN:
5182
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4832
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10622
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
68014
Other (OTH)
AF:
0.00
AC:
0
AN:
2090
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.425
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:
0.0000151

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:7
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Long QT syndrome Uncertain:2
Jan 23, 2025
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 alanine, which is neutral and non-polar, at codon 1132 of the KCNH2 protein (p.Pro1132Ala). This variant is present in population databases (rs786205422, gnomAD 0.009%). This missense change has been observed in individual(s) with long QT syndrome (PMID: 23631430, 23861362). ClinVar contains an entry for this variant (Variation ID: 191469). 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. -

Sep 23, 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 alanine at codon 1132 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). An experimental functional study has shown that this variant has no impact on channel function (PMID: 34930020). This variant has been reported in an individual affected with long-QT syndrome who also carried a pathogenic missense variant in the KCNQ1 gene (PMID: 23631430). It has also been reported in an individual suspected to be affected with coronary artery disease (PMID: 23861362) and in three individuals with no known arrhythmia phenotypes or other indications for cardiac genetic screening (PMID: 34930020). This variant has been identified in 3/165828 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. -

not specified Uncertain:1
Nov 13, 2024
Women's Health and Genetics/Laboratory Corporation of America, LabCorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Variant summary: KCNH2 c.3394C>G (p.Pro1132Ala) results in a non-conservative amino acid change in the encoded protein sequence. Three of five in-silico tools predict a damaging effect of the variant on protein function. The variant allele was found at a frequency of 1.8e-05 in 165828 control chromosomes (gnomAD). The available data on variant occurrences in the general population are insufficient to allow any conclusion about variant significance. c.3394C>G has been reported in the literature in individuals affected with Long QT syndrome without strong evidence of causality (Lieve_2013), and one individual had a co-occurring variant that some ClinVar submitters classified as pathogenic/likely pathogenic. This report does not provide unequivocal conclusions about association of the variant with Long QT Syndrome. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. The following publications have been ascertained in the context of this evaluation (PMID: 23631430, 23861362, 31696929). ClinVar contains an entry for this variant (Variation ID: 191469). Based on the evidence outlined above, the variant was classified as uncertain significance. -

not provided Uncertain:1
Jun 24, 2013
Biesecker Lab/Clinical Genomics Section, National Institutes of Health
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:research

- -

Cardiovascular phenotype Uncertain:1
Apr 13, 2022
Ambry Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The p.P1132A variant (also known as c.3394C>G), located in coding exon 15 of the KCNH2 gene, results from a C to G substitution at nucleotide position 3394. The proline at codon 1132 is replaced by alanine, an amino acid with highly similar properties, and is located in the C-terminal region of the protein. This variant was reported to co-occur with a KCNQ1 variant in an individual with mean QTc interval of 500ms and has been reported in an arrhythmia cohort (Lieve KV et al. Genet Test Mol Biomarkers, 2013 Jul;17:553-61; Li X et al. Ann Hum Genet, 2020 03;84:161-168). This alteration has also been reported as a secondary cardiac variant in an exome cohort (Ng D et al. Circ Cardiovasc Genet, 2013 Aug;6:337-46). This amino acid position is highly conserved in available vertebrate species. In addition, the in silico prediction for this alteration is inconclusive. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -

Short QT syndrome type 1;C3150943:Long QT syndrome 2 Uncertain:1
Aug 12, 2021
Fulgent Genetics, Fulgent Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Cardiac arrhythmia Uncertain:1
Jul 03, 2024
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 alanine at codon 1132 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). An experimental functional study has shown that this variant has no impact on channel function (PMID: 34930020). This variant has been reported in an individual affected with long-QT syndrome who also carried a pathogenic missense variant in the KCNQ1 gene (PMID: 23631430). It has also been reported in an individual suspected to be affected with coronary artery disease (PMID: 23861362) and in three individuals with no known arrhythmia phenotypes or other indications for cardiac genetic screening (PMID: 34930020). This variant has been identified in 3/165828 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
0.064
CardioboostArm
Benign
0.0000030
BayesDel_addAF
Uncertain
0.033
T
BayesDel_noAF
Uncertain
0.0
CADD
Benign
19
DANN
Uncertain
0.99
DEOGEN2
Uncertain
0.48
.;T
Eigen
Benign
-0.033
Eigen_PC
Benign
-0.0056
FATHMM_MKL
Uncertain
0.86
D
LIST_S2
Benign
0.69
T;T
M_CAP
Pathogenic
0.54
D
MetaRNN
Benign
0.27
T;T
MetaSVM
Pathogenic
0.98
D
MutationAssessor
Benign
1.5
.;L
PhyloP100
2.2
PrimateAI
Uncertain
0.59
T
PROVEAN
Benign
-1.6
N;N
REVEL
Uncertain
0.54
Sift
Uncertain
0.022
D;D
Sift4G
Uncertain
0.048
D;T
Polyphen
0.52
P;P
Vest4
0.33
MutPred
0.17
.;Loss of glycosylation at P1132 (P = 0.0372);
MVP
0.64
MPC
0.23
ClinPred
0.076
T
GERP RS
4.2
Varity_R
0.068
gMVP
0.26
Mutation Taster
=8/92
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: rs786205422; hg19: chr7-150642539; API