11-2445250-ACGCGCCCAT-ACGCGCCCATCGCGCCCAT

Variant summary

Our verdict is Benign. Variant got -7 ACMG points: 2P and 9B. PM4BP6BS1BS2

The NM_000218.3(KCNQ1):​c.160_168dupATCGCGCCC​(p.Ile54_Pro56dup) variant causes a conservative inframe insertion change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00173 in 1,199,452 control chromosomes in the GnomAD database, including 33 homozygotes. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

Frequency

Genomes: 𝑓 0.0088 ( 21 hom., cov: 32)
Exomes 𝑓: 0.00073 ( 12 hom. )

Consequence

KCNQ1
NM_000218.3 conservative_inframe_insertion

Scores

Not classified

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:1U:2B:9

Conservation

PhyloP100: -0.203
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]

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ACMG classification

Classification made for transcript

Verdict is Benign. Variant got -7 ACMG points.

PM4
Nonframeshift variant in NON repetitive region in NM_000218.3.
BP6
Variant 11-2445250-A-ACGCGCCCAT is Benign according to our data. Variant chr11-2445250-A-ACGCGCCCAT is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 42487.We mark this variant Likely_benign, oryginal submissions are: {Likely_benign=2, Benign=6, Uncertain_significance=2}.
BS1
Variant frequency is greater than expected in population afr. gnomad4 allele frequency = 0.00881 (1307/148370) while in subpopulation AFR AF= 0.0308 (1261/40938). AF 95% confidence interval is 0.0294. There are 21 homozygotes in gnomad4. There are 612 alleles in male gnomad4 subpopulation. Median coverage is 32. This position pass quality control queck.
BS2
High Homozygotes in GnomAd4 at 21 AD,AR,Digenic gene

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
KCNQ1NM_000218.3 linkc.160_168dupATCGCGCCC p.Ile54_Pro56dup conservative_inframe_insertion Exon 1 of 16 ENST00000155840.12 NP_000209.2 P51787-1Q96AI9
KCNQ1NM_001406836.1 linkc.160_168dupATCGCGCCC p.Ile54_Pro56dup conservative_inframe_insertion Exon 1 of 15 NP_001393765.1
KCNQ1NM_001406838.1 linkc.160_168dupATCGCGCCC p.Ile54_Pro56dup conservative_inframe_insertion Exon 1 of 11 NP_001393767.1
KCNQ1NM_001406837.1 linkc.-203_-195dupATCGCGCCC 5_prime_UTR_variant Exon 1 of 17 NP_001393766.1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
KCNQ1ENST00000155840.12 linkc.160_168dupATCGCGCCC p.Ile54_Pro56dup conservative_inframe_insertion Exon 1 of 16 1 NM_000218.3 ENSP00000155840.2 P51787-1
KCNQ1ENST00000646564.2 linkc.160_168dupATCGCGCCC p.Ile54_Pro56dup conservative_inframe_insertion Exon 1 of 11 ENSP00000495806.2 A0A2R8YEQ9
KCNQ1ENST00000496887.7 linkc.24-125_24-117dupATCGCGCCC intron_variant Intron 1 of 15 5 ENSP00000434560.2 E9PPZ0
KCNQ1ENST00000345015.4 linkn.-72_-71insCGCGCCCAT upstream_gene_variant 1

Frequencies

GnomAD3 genomes
AF:
0.00880
AC:
1305
AN:
148264
Hom.:
21
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.0308
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.00201
Gnomad ASJ
AF:
0.00
Gnomad EAS
AF:
0.00
Gnomad SAS
AF:
0.00
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00318
Gnomad NFE
AF:
0.000135
Gnomad OTH
AF:
0.00294
GnomAD3 exomes
AF:
0.000258
AC:
2
AN:
7752
Hom.:
0
AF XY:
0.000207
AC XY:
1
AN XY:
4828
show subpopulations
Gnomad AFR exome
AF:
0.00862
Gnomad AMR exome
AF:
0.00
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad SAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.000311
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.000730
AC:
767
AN:
1051082
Hom.:
12
Cov.:
30
AF XY:
0.000659
AC XY:
332
AN XY:
503788
show subpopulations
Gnomad4 AFR exome
AF:
0.0285
Gnomad4 AMR exome
AF:
0.00195
Gnomad4 ASJ exome
AF:
0.00
Gnomad4 EAS exome
AF:
0.00
Gnomad4 SAS exome
AF:
0.0000409
Gnomad4 FIN exome
AF:
0.00
Gnomad4 NFE exome
AF:
0.0000664
Gnomad4 OTH exome
AF:
0.00234
GnomAD4 genome
AF:
0.00881
AC:
1307
AN:
148370
Hom.:
21
Cov.:
32
AF XY:
0.00845
AC XY:
612
AN XY:
72398
show subpopulations
Gnomad4 AFR
AF:
0.0308
Gnomad4 AMR
AF:
0.00200
Gnomad4 ASJ
AF:
0.00
Gnomad4 EAS
AF:
0.00
Gnomad4 SAS
AF:
0.00
Gnomad4 FIN
AF:
0.00
Gnomad4 NFE
AF:
0.000135
Gnomad4 OTH
AF:
0.00291
Asia WGS
AF:
0.00371
AC:
12
AN:
3244

ClinVar

Significance: Conflicting classifications of pathogenicity
Submissions summary: Pathogenic:1Uncertain:2Benign:9
Revision: criteria provided, conflicting classifications
LINK: link

Submissions by phenotype

not specified Benign:3
Jun 24, 2024
Women's Health and Genetics/Laboratory Corporation of America, LabCorp
Significance: Benign
Review Status: criteria provided, single submitter
Collection Method: clinical testing

Variant summary: KCNQ1 c.160_168dupATCGCGCCC (p.Ile54_Pro56dup) results in an in-frame duplication that is predicted to duplicate three amino acids into the encoded protein. The variant allele was found at a frequency of 0.0017 in 1200626 control chromosomes, predominantly at a frequency of 0.03 within the African or African-American subpopulation in the gnomAD database (v4), including 31 homozygotes. The observed variant frequency within African or African-American control individuals in the gnomAD database is approximately 300 fold of the estimated maximal expected allele frequency for a pathogenic variant in KCNQ1 causing Arrhythmia phenotype (0.0001). c.160_168dupATCGCGCCC has been reported in the literature in individuals affected with Arrhythmia as well as in control population (e.g. Abraham_2010, Berge_2008, Ackerman_2003, Tester_2005_01, Kapa_2009, Hassnan_2017, Millat_2014). In a family with familial atrial fibrillation, this variant was reported with inconclusive co-segregation of this variant with disease (Abraham_2010). This family however, was not comprehensively screened for mutations in all susceptibility genes. Co-occurrences with other pathogenic variants have been reported (KCNQ1 c.674C>T, p.Ser225Leu; KCNH2 c.1841C>T, p.Ala614Val) in our internal database. In vitro functional study detected partial defect of the channel properties (Abraham_2010), suggesting that it could be a functional polymorphism.. The following publications have been ascertained in the context of this evaluation (PMID: 14661677, 17210839, 15913580, 19841300, 19646991, 18752142, 22947121, 22818067, 24687331, 28438721). ClinVar contains an entry for this variant (Variation ID: 42487). Based on the evidence outlined above, the variant was classified as benign. -

Aug 17, 2016
Eurofins Ntd Llc (ga)
Significance: Benign
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

May 18, 2017
Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine
Significance: Benign
Review Status: criteria provided, single submitter
Collection Method: clinical testing

p.Ile54_Pro56dup in Exon 1 of KCNQ1: This variant is not expected to have clinic al significance because it has been identified in 2.9% (250/8370) of African ch romosomes by the Genome Aggregation Database (gnomAD, http://gnomad.broadinstitu te.org; dbSNP rs561562768). It has been reported in two individuals with cardia c arrhythmias (1/182 LQTS, Berge 2008; 1/231 AF, Abraham 2010) and segregated in three affected individuals in one family, though phenotypes were unknown in 2 o ther mutation carriers (Abraham 2010). In addition, one study demonstrated some alteration of channel properties (Abraham 2010) although this study was only in vitro such that correlation to a clinical phenotype was not possible. This varia nt was also identified in several healthy control cohorts (0.3% 4/1488 chromosom es, Ackerman 2003; 1/364 chromosomes, Arnestad 2007; 2.1% (2/94) African-America n control chromosomes, Abraham 2010) and is now listed in the KCNQ1 database as a benign variant (http://www.fsm.it/cardmoc/kvlqt1poly.htm). In summary, given t he high frequency of the variant in spite of the reports in the literature, this variant is benign for a reasonably penetrant disease variant and insufficient b iological evidence for a clinically relevant impact to protein function, we have classified this variant as likely benign. -

not provided Benign:3
Sep 21, 2023
ARUP Laboratories, Molecular Genetics and Genomics, ARUP Laboratories
Significance: Likely benign
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

Jul 17, 2018
GeneDx
Significance: Benign
Review Status: criteria provided, single submitter
Collection Method: clinical testing

This variant is associated with the following publications: (PMID: 18752142, 14661677, 17210839, 19646991, 28438721, 32048431, 30847666) -

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

KCNQ1: BS1, BS2 -

Cardiovascular phenotype Uncertain:2
Feb 27, 2013
Ambry Genetics
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

Mar 02, 2013
Ambry Genetics
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

Atrial fibrillation, familial, 3 Pathogenic:1
Jan 01, 2010
OMIM
Significance: Pathogenic
Review Status: no assertion criteria provided
Collection Method: literature only

- -

KCNQ1-related disorder Benign:1
Mar 09, 2020
PreventionGenetics, part of Exact Sciences
Significance: Likely benign
Review Status: no assertion criteria provided
Collection Method: clinical testing

This variant is classified as likely benign based on ACMG/AMP sequence variant interpretation guidelines (Richards et al. 2015 PMID: 25741868, with internal and published modifications). -

Ventricular fibrillation Benign:1
May 20, 2019
Center for Advanced Laboratory Medicine, UC San Diego Health, University of California San Diego
Significance: Likely benign
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

Long QT syndrome Benign:1
Jan 31, 2025
Labcorp Genetics (formerly Invitae), Labcorp
Significance: Benign
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction

Splicing

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

Publications

LitVar

Below is the list of publications found by LitVar. It may be empty.

Other links and lift over

dbSNP: rs397515877; hg19: chr11-2466480; API