11-2588718-GAAAA-GAAA

Variant summary

Our verdict is Pathogenic. The variant received 16 ACMG points: 16P and 0B. PVS1PP5_Very_Strong

The NM_000218.3(KCNQ1):​c.1265delA​(p.Lys422SerfsTer10) variant causes a frameshift change. The variant allele was found at a frequency of 0.00000868 in 1,613,158 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Pathogenic (★★). Synonymous variant affecting the same amino acid position (i.e. K422K) has been classified as Likely benign. Variant results in nonsense mediated mRNA decay.

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 33)
Exomes 𝑓: 0.0000089 ( 0 hom. )

Consequence

KCNQ1
NM_000218.3 frameshift

Scores

Not classified

Clinical Significance

Pathogenic criteria provided, multiple submitters, no conflicts P:12

Conservation

PhyloP100: 5.91

Publications

9 publications found
Variant links:
Genes affected
KCNQ1 (HGNC:6294): (potassium voltage-gated channel subfamily Q member 1) This gene encodes a voltage-gated potassium channel required for repolarization phase of the cardiac action potential. This protein can form heteromultimers with two other potassium channel proteins, KCNE1 and KCNE3. Mutations in this gene are associated with hereditary long QT syndrome 1 (also known as Romano-Ward syndrome), Jervell and Lange-Nielsen syndrome, and familial atrial fibrillation. This gene exhibits tissue-specific imprinting, with preferential expression from the maternal allele in some tissues, and biallelic expression in others. This gene is located in a region of chromosome 11 amongst other imprinted genes that are associated with Beckwith-Wiedemann syndrome (BWS), and itself has been shown to be disrupted by chromosomal rearrangements in patients with BWS. Alternatively spliced transcript variants have been found for this gene. [provided by RefSeq, Aug 2011]
KCNQ1 Gene-Disease associations (from GenCC):
  • long QT syndrome
    Inheritance: AD Classification: DEFINITIVE Submitted by: ClinGen
  • long QT syndrome 1
    Inheritance: AD, AR Classification: DEFINITIVE, STRONG Submitted by: Labcorp Genetics (formerly Invitae), G2P
  • Jervell and Lange-Nielsen syndrome
    Inheritance: AR Classification: DEFINITIVE Submitted by: ClinGen
  • Jervell and Lange-Nielsen syndrome 1
    Inheritance: AR Classification: DEFINITIVE, STRONG Submitted by: PanelApp Australia, Labcorp Genetics (formerly Invitae), G2P
  • atrial fibrillation, familial, 3
    Inheritance: AD Classification: STRONG Submitted by: Labcorp Genetics (formerly Invitae)
  • short QT syndrome
    Inheritance: AD Classification: STRONG, SUPPORTIVE Submitted by: ClinGen, Orphanet
  • short QT syndrome type 2
    Inheritance: AD Classification: STRONG Submitted by: Labcorp Genetics (formerly Invitae), G2P
  • familial atrial fibrillation
    Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
  • Jervell and Lange-Nielsen syndrome
    Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
  • hypertrophic cardiomyopathy
    Inheritance: AD Classification: NO_KNOWN Submitted by: ClinGen

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Pathogenic. The variant received 16 ACMG points.

PVS1
Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.
PP5
Variant 11-2588718-GA-G is Pathogenic according to our data. Variant chr11-2588718-GA-G is described in ClinVar as Pathogenic. ClinVar VariationId is 52973.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
KCNQ1NM_000218.3 linkc.1265delA p.Lys422SerfsTer10 frameshift_variant Exon 10 of 16 ENST00000155840.12 NP_000209.2

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
KCNQ1ENST00000155840.12 linkc.1265delA p.Lys422SerfsTer10 frameshift_variant Exon 10 of 16 1 NM_000218.3 ENSP00000155840.2

Frequencies

GnomAD3 genomes
AF:
0.00000658
AC:
1
AN:
151936
Hom.:
0
Cov.:
33
show subpopulations
Gnomad AFR
AF:
0.0000242
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:
0.00
GnomAD2 exomes
AF:
0.0000120
AC:
3
AN:
250000
AF XY:
0.0000148
show subpopulations
Gnomad AFR exome
AF:
0.0000620
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:
0.00000885
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.00000890
AC:
13
AN:
1461222
Hom.:
0
Cov.:
32
AF XY:
0.00000550
AC XY:
4
AN XY:
726892
show subpopulations
African (AFR)
AF:
0.0000299
AC:
1
AN:
33474
American (AMR)
AF:
0.00
AC:
0
AN:
44704
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26132
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39700
South Asian (SAS)
AF:
0.0000116
AC:
1
AN:
86200
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53118
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5628
European-Non Finnish (NFE)
AF:
0.00000899
AC:
10
AN:
1111884
Other (OTH)
AF:
0.0000166
AC:
1
AN:
60382
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.502
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:
0.00000658
AC:
1
AN:
151936
Hom.:
0
Cov.:
33
AF XY:
0.00
AC XY:
0
AN XY:
74198
show subpopulations
African (AFR)
AF:
0.0000242
AC:
1
AN:
41370
American (AMR)
AF:
0.00
AC:
0
AN:
15258
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3472
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5182
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4810
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10568
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
67960
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
Alfa
AF:
0.0000712
Hom.:
0
Bravo
AF:
0.00000756

ClinVar

Significance: Pathogenic
Submissions summary: Pathogenic:12
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

not provided Pathogenic:6
Feb 19, 2019
Revvity Omics, Revvity
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Jul 17, 2025
GeneDx
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Reported in association with sinus bradycardia and LQTS or suspected LQTS in published literature and referred for genetic testing at GeneDx (PMID: 14998624, 19841300, 22456477, 23098067, 32048431); 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); This variant is associated with the following publications: (PMID: 23098067, 19716085, 32048431, 32421437, 30847666, 34505893, 22456477, 19841300, 37568094, 14998624) -

Aug 18, 2021
AiLife Diagnostics, AiLife Diagnostics
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Feb 16, 2025
Laboratory of Genetics, Children's Clinical University Hospital Latvia
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Sep 16, 2018
Gharavi Laboratory, Columbia University
Significance:Pathogenic
Review Status:no assertion criteria provided
Collection Method:research

- -

Apr 01, 2024
CeGaT Center for Human Genetics Tuebingen
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

KCNQ1: PVS1, PM2, PS4:Moderate -

Long QT syndrome Pathogenic:3
May 08, 2023
Women's Health and Genetics/Laboratory Corporation of America, LabCorp
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Variant summary: KCNQ1 c.1265delA (p.Lys422SerfsX10) results in a premature termination codon, predicted to cause a truncation of the encoded protein or absence of the protein due to nonsense mediated decay, which are commonly known mechanisms for disease. The variant allele was found at a frequency of 1.2e-05 in 250000 control chromosomes. c.1265delA has been reported in the literature in individuals affected with Long QT Syndrome (Kapplinger_2009). These data indicate that the variant may be associated with disease. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. Eight clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014 without evidence for independent evaluation. All laboratories classified the variant as pathogenic. Based on the evidence outlined above, the variant was classified as pathogenic. -

Sep 21, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change creates a premature translational stop signal (p.Lys422Serfs*10) in the KCNQ1 gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in KCNQ1 are known to be pathogenic (PMID: 9323054, 19862833). The frequency data for this variant in the population databases is considered unreliable, as metrics indicate poor data quality at this position in the gnomAD database. This premature translational stop signal has been observed in individual(s) with long QT syndrome (PMID: 14998624, 19716085, 19841300, 22456477, 23098067). ClinVar contains an entry for this variant (Variation ID: 52973). For these reasons, this variant has been classified as Pathogenic. -

Sep 16, 2024
All of Us Research Program, National Institutes of Health
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This variant deletes 1 nucleotide in exon 10 of the KCNQ1 gene, creating a frameshift and premature translation stop signal. This variant is expected to result in an absent or non-functional protein product. To our knowledge, functional assays have not been performed for this variant. This variant has been reported in several individuals affected with long QT syndrome (PMID: 19716085, 19841300, 22456477, 23098067). This variant has not been identified in the general population by the Genome Aggregation Database (gnomAD). Loss of KCNQ1 function is a known mechanism of disease. Based on available evidence, this variant is classified as Pathogenic. -

Long QT syndrome 1 Pathogenic:1
Dec 17, 2019
Center For Human Genetics And Laboratory Diagnostics, Dr. Klein, Dr. Rost And Colleagues
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Cardiovascular phenotype Pathogenic:1
Dec 20, 2024
Ambry Genetics
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The c.1265delA (p.K422Sfs*10) alteration, located in exon 10 (coding exon 10) of the KCNQ1 gene, consists of a deletion of one nucleotide at position 1265, causing a translational frameshift with a predicted alternate stop codon after 10 amino acids. This alteration is expected to result in loss of function by premature protein truncation or nonsense-mediated mRNA decay. for KCNQ1-related long QT syndrome; however, it is unlikely to be causative of KCNQ1-related short QT syndrome. Based on data from gnomAD, this allele has an overall frequency of 0.001% (3/250000) total alleles studied. The highest observed frequency was 0.006% (1/16132) of African alleles. This variant has been reported in the heterozygous state in multiple individuals with features consistent with long QT syndrome (Kapa, 2009; Kapplinger, 2009; van Lint 2019; Mazzaccara, 2022). This variant has also been identified in the compound heterozygous state in at least one individual with clinical features consistent with autosomal recessive Jervell and Lange-Nielsen syndrome (Zhao, 2023). Based on the available evidence, this alteration is classified as pathogenic. -

Cardiac arrhythmia Pathogenic:1
Feb 21, 2024
Color Diagnostics, LLC DBA Color Health
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This variant deletes 1 nucleotide in exon 10 of the KCNQ1 gene, creating a frameshift and premature translation stop signal. This variant is expected to result in an absent or non-functional protein product. To our knowledge, functional assays have not been performed for this variant. This variant has been reported in several individuals affected with long QT syndrome (PMID: 19716085, 19841300, 22456477, 23098067). This variant has not been identified in the general population by the Genome Aggregation Database (gnomAD). Loss of KCNQ1 function is a known mechanism of disease. Based on available evidence, this variant is classified as Pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
PhyloP100
5.9
Mutation Taster
=0/200
disease causing (ClinVar)

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: rs397508083; hg19: chr11-2609948; COSMIC: COSV50100003; API