7-150947832-C-CGCCCG

Variant summary

Our verdict is Pathogenic. The variant received 18 ACMG points: 18P and 0B. PVS1PM2PP5_Very_Strong

The NM_000238.4(KCNH2):​c.2734_2738dupCGGGC​(p.Ala915ArgfsTer61) variant causes a frameshift change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000728 in 1,373,282 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Likely pathogenic (★★). Synonymous variant affecting the same amino acid position (i.e. A913A) has been classified as Benign. Variant results in nonsense mediated mRNA decay.

Frequency

Genomes: not found (cov: 33)
Exomes 𝑓: 7.3e-7 ( 0 hom. )

Consequence

KCNH2
NM_000238.4 frameshift

Scores

Not classified

Clinical Significance

Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:3

Conservation

PhyloP100: 0.134

Publications

4 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: Pathogenic. The variant received 18 ACMG points.

PVS1
Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.
PM2
Very rare variant in population databases, with high coverage;
PP5
Variant 7-150947832-C-CGCCCG is Pathogenic according to our data. Variant chr7-150947832-C-CGCCCG is described in ClinVar as Pathogenic/Likely_pathogenic. ClinVar VariationId is 200795.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
KCNH2NM_000238.4 linkc.2734_2738dupCGGGC p.Ala915ArgfsTer61 frameshift_variant Exon 12 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.2734_2738dupCGGGC p.Ala915ArgfsTer61 frameshift_variant Exon 12 of 15 1 NM_000238.4 ENSP00000262186.5 Q12809-1

Frequencies

GnomAD3 genomes
Cov.:
33
GnomAD2 exomes
AF:
0.00000824
AC:
1
AN:
121350
AF XY:
0.0000151
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:
0.000171
Gnomad NFE exome
AF:
0.00
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
7.28e-7
AC:
1
AN:
1373282
Hom.:
0
Cov.:
36
AF XY:
0.00000148
AC XY:
1
AN XY:
676890
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
31252
American (AMR)
AF:
0.00
AC:
0
AN:
34356
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
24304
East Asian (EAS)
AF:
0.00
AC:
0
AN:
35572
South Asian (SAS)
AF:
0.00
AC:
0
AN:
77390
European-Finnish (FIN)
AF:
0.0000287
AC:
1
AN:
34836
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
4062
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
1074240
Other (OTH)
AF:
0.00
AC:
0
AN:
57270
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
GnomAD4 genome
Cov.:
33

ClinVar

Significance: Pathogenic/Likely pathogenic
Submissions summary: Pathogenic:3
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Long QT syndrome 2 Pathogenic:1
Aug 27, 2024
KardioGenetik, Herz- und Diabeteszentrum NRW
Significance:Likely pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

not provided Pathogenic:1
May 27, 2025
GeneDx
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Frameshift variant predicted to result in protein truncation or nonsense mediated decay in a gene for which loss of function is a known mechanism of disease; Not observed at significant frequency in large population cohorts (gnomAD); Also known as p.R912fs+63X and 2733_2737dup; This variant is associated with the following publications: (PMID: 18441445, 26669661, 36861347) -

Cardiovascular phenotype Pathogenic:1
Dec 07, 2022
Ambry Genetics
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The c.2734_2738dupCGGGC pathogenic mutation, located in coding exon 12 of the KCNH2 gene, results from a duplication of CGGGC at nucleotide position 2734, causing a translational frameshift with a predicted alternate stop codon (p.A915Rfs*61). This alteration has been reported in association with long QT syndrome (Nagaoka I et al. Circ J, 2008 May;72:694-9; Itoh H et al. Eur J Hum Genet, 2016 Aug;24:1160-6). This variant is considered to be rare based on population cohorts in the Genome Aggregation Database (gnomAD). This alteration is expected to result in loss of function by premature protein truncation or nonsense-mediated mRNA decay. As such, this alteration is interpreted as a disease-causing mutation. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
PhyloP100
0.13
Mutation Taster
=0/200
disease causing (ClinVar)

Splicing

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

Publications

Other links and lift over

dbSNP: rs794728502; hg19: chr7-150644920; API