7-150947372-GC-GCCCC

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.3105_3107dupGGG​(p.Gly1036dup) variant causes a disruptive inframe insertion change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000452 in 1,547,114 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★★). Synonymous variant affecting the same amino acid position (i.e. G1036G) has been classified as Likely benign.

Frequency

Genomes: 𝑓 0.000033 ( 0 hom., cov: 33)
Exomes 𝑓: 0.0000014 ( 0 hom. )

Consequence

KCNH2
NM_000238.4 disruptive_inframe_insertion

Scores

Not classified

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:3

Conservation

PhyloP100: 1.40

Publications

5 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 5 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 2 benign, 28 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 5 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.3105_3107dupGGG p.Gly1036dup disruptive_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.3105_3107dupGGG p.Gly1036dup disruptive_inframe_insertion Exon 13 of 15 1 NM_000238.4 ENSP00000262186.5 Q12809-1

Frequencies

GnomAD3 genomes
AF:
0.0000329
AC:
5
AN:
152022
Hom.:
0
Cov.:
33
show subpopulations
Gnomad AFR
AF:
0.0000966
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:
0.00
Gnomad OTH
AF:
0.000478
GnomAD2 exomes
AF:
0.00000692
AC:
1
AN:
144468
AF XY:
0.0000128
show subpopulations
Gnomad AFR exome
AF:
0.000150
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:
0.00
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.00000143
AC:
2
AN:
1395092
Hom.:
0
Cov.:
36
AF XY:
0.00000291
AC XY:
2
AN XY:
688188
show subpopulations
African (AFR)
AF:
0.0000631
AC:
2
AN:
31684
American (AMR)
AF:
0.00
AC:
0
AN:
35666
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
25116
East Asian (EAS)
AF:
0.00
AC:
0
AN:
35916
South Asian (SAS)
AF:
0.00
AC:
0
AN:
79144
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
45544
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5186
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
1078954
Other (OTH)
AF:
0.00
AC:
0
AN:
57882
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.400
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

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:
0.0000329
AC:
5
AN:
152022
Hom.:
0
Cov.:
33
AF XY:
0.0000135
AC XY:
1
AN XY:
74248
show subpopulations
African (AFR)
AF:
0.0000966
AC:
4
AN:
41390
American (AMR)
AF:
0.00
AC:
0
AN:
15284
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3472
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5144
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4828
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10616
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
67968
Other (OTH)
AF:
0.000478
AC:
1
AN:
2092
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.485
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:
0.00
Hom.:
0
Bravo
AF:
0.0000264

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:3
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Long QT syndrome Uncertain:1
Oct 12, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This variant, c.3105_3107dup, results in the insertion of 1 amino acid(s) of the KCNH2 protein (p.Gly1036dup), 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 not been reported in the literature in individuals affected with KCNH2-related conditions. ClinVar contains an entry for this variant (Variation ID: 845975). 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
Mar 14, 2024
Ambry Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The c.3105_3107dupGGG variant (also known as p.G1036dup), located in coding exon 13 of the KCNH2 gene, results from an in-frame duplication of GGG at nucleotide positions 3105 to 3107. This results in the duplication of an extra glycine residue between codons 1036 and 1037. This amino acid position is not 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). Based on the available evidence, the clinical significance of this alteration remains unclear. -

Short QT syndrome type 1;C3150943:Long QT syndrome 2 Uncertain:1
Nov 03, 2021
Fulgent Genetics, Fulgent Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
PhyloP100
1.4
Mutation Taster
=66/34
polymorphism

Splicing

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

Publications

Other links and lift over

dbSNP: rs794728469; hg19: chr7-150644460; API