rs1060499872

Variant summary

Our verdict is Uncertain significance. The variant received 2 ACMG points: 3P and 1B. PM1PM4_SupportingBS2_Supporting

The NM_000238.4(KCNH2):​c.3098_3100dupGGC​(p.Arg1033dup) variant causes a conservative inframe insertion change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000168 in 1,548,526 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★★).

Frequency

Genomes: 𝑓 0.000046 ( 0 hom., cov: 33)
Exomes 𝑓: 0.000014 ( 0 hom. )

Consequence

KCNH2
NM_000238.4 conservative_inframe_insertion

Scores

Not classified

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:9

Conservation

PhyloP100: 1.01

Publications

0 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 2 ACMG points.

PM1
In a hotspot region, there are 4 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 1 benign, 13 uncertain in NM_000238.4
PM4
Nonframeshift variant in NON repetitive region in NM_000238.4. Strenght limited to Supporting due to length of the change: 1aa.
BS2
High AC in GnomAd4 at 7 AD gene. Variant has AC lower than other variant known as pathogenic in the gene, so the strength is limited to Supporting.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
KCNH2NM_000238.4 linkc.3098_3100dupGGC p.Arg1033dup conservative_inframe_insertion Exon 13 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.3098_3100dupGGC p.Arg1033dup conservative_inframe_insertion Exon 13 of 15 1 NM_000238.4 ENSP00000262186.5 Q12809-1

Frequencies

GnomAD3 genomes
AF:
0.0000460
AC:
7
AN:
152080
Hom.:
0
Cov.:
33
show subpopulations
Gnomad AFR
AF:
0.0000483
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:
0.0000736
Gnomad OTH
AF:
0.00
GnomAD4 exome
AF:
0.0000136
AC:
19
AN:
1396446
Hom.:
0
Cov.:
35
AF XY:
0.0000116
AC XY:
8
AN XY:
688866
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
31728
American (AMR)
AF:
0.0000280
AC:
1
AN:
35668
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
25120
East Asian (EAS)
AF:
0.00
AC:
0
AN:
35966
South Asian (SAS)
AF:
0.00
AC:
0
AN:
79204
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
46422
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5250
European-Non Finnish (NFE)
AF:
0.0000158
AC:
17
AN:
1079196
Other (OTH)
AF:
0.0000173
AC:
1
AN:
57892
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.509
Heterozygous variant carriers
0
1
2
4
5
6
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:
0.0000460
AC:
7
AN:
152080
Hom.:
0
Cov.:
33
AF XY:
0.0000404
AC XY:
3
AN XY:
74294
show subpopulations
African (AFR)
AF:
0.0000483
AC:
2
AN:
41416
American (AMR)
AF:
0.00
AC:
0
AN:
15282
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3472
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5160
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4828
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10626
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.0000736
AC:
5
AN:
67980
Other (OTH)
AF:
0.00
AC:
0
AN:
2088
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.496
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:
0.0000712
Hom.:
0
Bravo
AF:
0.0000302

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:9
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

not provided Uncertain:4
Feb 11, 2022
AiLife Diagnostics, AiLife Diagnostics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Jul 02, 2025
GeneDx
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Reported as c.3101_3103insGGC, due to alternate nomenclature, in one individual referred for LQTS genetic testing (PMID: 19716085); In-frame duplication of 1 amino acid in a non-repeat region; This variant is associated with the following publications: (PMID: 35130036, 19716085) -

-
Breakthrough Genomics, Breakthrough Genomics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:not provided

- -

Aug 01, 2023
CeGaT Center for Human Genetics Tuebingen
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

KCNH2: PM2, PM4 -

not specified Uncertain:1
Jun 23, 2016
Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Variant identified in a genome or exome case(s) and assessed due to predicted null impact of the variant or pathogenic assertions in the literature or databases. Disclaimer: This variant has not undergone full assessment. The following are preliminary notes: Only reported in 1 proband -

Long QT syndrome Uncertain:1
Jan 31, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This variant, c.3098_3100dup, results in the insertion of 1 amino acid(s) of the KCNH2 protein (p.Arg1033dup), but otherwise preserves the integrity of the reading frame. This variant is present in population databases (no rsID available, gnomAD 0.02%). This variant has been observed in individual(s) with Long QT syndrome (PMID: 19716085). This variant is also known as c.3101_3103insGGC (p.1034insR). ClinVar contains an entry for this variant (Variation ID: 402997). Experimental studies and prediction algorithms are not available or were not evaluated, and the functional significance of this variant is currently unknown. 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. -

Cardiovascular phenotype Uncertain:1
Oct 15, 2024
Ambry Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The c.3098_3100dupGGC variant (also known as p.R1033dup) is located in coding exon 13 of the KCNH2 gene. This variant results from an in-frame duplication of GGC at nucleotide positions 3098 to 3100. This results in the duplication of an arginine residue at codon 1033. In a study of long QT syndrome clinical genetic testing, this alteration (referred to as c.3101_3103insGGC, p.1034insR) was reported in one patient; however, clinical details were limited (Kapplinger JD et al. Heart Rhythm, 2009 Sep;6:1297-303). This amino acid position is well conserved in available vertebrate species. In addition, the in silico prediction for this alteration is inconclusive (Choi Y et al. PLoS ONE. 2012; 7(10):e46688). 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
Oct 06, 2021
Fulgent Genetics, Fulgent Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Cardiac arrhythmia Uncertain:1
May 15, 2024
Color Diagnostics, LLC DBA Color Health
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This variant causes a duplication of one amino acid at codon 1033 in the KCNH2 protein. To our knowledge, functional studies have not been reported for this variant. This variant (as known as c.3101_3103insGGC; p.1034insR) has been reported in an individual suspected of having long QT syndrome (PMID: 19716085). This variant has been identified in 4/31294 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
PhyloP100
1.0
Mutation Taster
=56/44
polymorphism

Splicing

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

Other links and lift over

dbSNP: rs1060499872; hg19: chr7-150644467; API