rs199472677

Variant names:

Your query was ambiguous. Multiple possible variants found:

Variant summary

Our verdict is Uncertain significance. The variant received 0 ACMG points: 0P and 0B.

This summary comes from the ClinGen Evidence Repository: NM_000218.3(KCNQ1):c.328G>A is a missense variant predicted to cause substitution of valine by isoleucine at amino acid 110 (p.Val110Ile). This variant is present in gnomAD v.4.1.0 at a maximum allele frequency of 0.00008307, with 98 alleles / 1,179,710 total alleles in the European (non-Finnish) population, which is higher than the ClinGen Potassium Channel Arrhythmia VCEP PM2_Supporting threshold of <0.00001, but lower than the BS1 threshold of >0.0004, so neither criterion is met. Functional studies have been performed on this variant (PMID:21164565, 29532034, and 29021305) but do not meet VCEP criteria for PS3/BS3. The computational predictor REVEL gives a score of 0.562, which is below the ClinGen Potassium Channel Arrhythmia VCEP PP3 threshold of >0.75 but higher than the BP4 threshold of <0.25 and does not strongly predict a damaging effect on KCNQ1 function. The computational splicing predictor SpliceAI gives a score of 0.00, which is lower than the ClinGen Potassium Channel Arrhythmia VCEP PP3 threshold of greater than or equal to 0.2 and does not strongly predict a damaging effect on KCNQ1 splicing. In summary, this variant meets the criteria to be classified as a variant of uncertain significance for long QT syndrome 1 based on the ACMG/AMP criteria applied, as specified by the ClinGen Potassium Channel Arrhythmia VCEP: None. (VCEP specifications version 1.0.0; date of approval 03/04/2025). LINK:https://erepo.genome.network/evrepo/ui/classification/CA006800/MONDO:0100316/112

Frequency

Genomes: 𝑓 0.000085 ( 0 hom., cov: 32)

Exomes 𝑓: 0.000061 ( 0 hom. )

Consequence

KCNQ1
NM_000218.3 missense

Scores

Clinical Significance

Uncertain significance reviewed by expert panel U:7B:1O:1

Conservation

PhyloP100: 6.89

Publications

12 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

KCNQ1 links:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Uncertain_significance. The variant received 0 ACMG points.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
KCNQ1	NM_000218.3 link	c.328G>A	p.Val110Ile	missense_variant	Exon 1 of 16	ENST00000155840.12	NP_000209.2	P51787-1Q96AI9
KCNQ1	NM_001406836.1 link	c.328G>A	p.Val110Ile	missense_variant	Exon 1 of 15		NP_001393765.1
KCNQ1	NM_001406838.1 link	c.328G>A	p.Val110Ile	missense_variant	Exon 1 of 11		NP_001393767.1
KCNQ1	NM_001406837.1 link	c.-35G>A		5_prime_UTR_variant	Exon 1 of 17		NP_001393766.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
KCNQ1	ENST00000155840.12 link	c.328G>A	p.Val110Ile	missense_variant	Exon 1 of 16	1	NM_000218.3	ENSP00000155840.2		P51787-1

Frequencies

GnomAD3 genomes

AF:

0.0000855

AC:

AN:

152118

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00

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:

0.000191

Gnomad OTH

AF:

0.00

GnomAD2 exomes

AF:

0.0000626

AC:

AN:

223660

AF XY:

0.0000726

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.000105

Gnomad EAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.000129

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000609

AC:

AN:

1445584

Hom.:

Cov.:

AF XY:

0.0000653

AC XY:

AN XY:

719546

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

33466

American (AMR)

AF:

0.00

AC:

AN:

44676

Ashkenazi Jewish (ASJ)

AF:

0.0000383

AC:

AN:

26104

East Asian (EAS)

AF:

0.00

AC:

AN:

39676

South Asian (SAS)

AF:

0.00

AC:

AN:

86128

European-Finnish (FIN)

AF:

0.00

AC:

AN:

37828

Middle Eastern (MID)

AF:

0.000174

AC:

AN:

5754

European-Non Finnish (NFE)

AF:

0.0000765

AC:

AN:

1111704

Other (OTH)

AF:

0.0000166

AC:

AN:

60248

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.482

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Exome Het

Variant carriers

<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:

0.0000855

AC:

AN:

152118

Hom.:

Cov.:

AF XY:

0.0000807

AC XY:

AN XY:

74306

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

41460

American (AMR)

AF:

0.00

AC:

AN:

15282

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3470

East Asian (EAS)

AF:

0.00

AC:

AN:

5158

South Asian (SAS)

AF:

0.00

AC:

AN:

4832

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10596

Middle Eastern (MID)

AF:

0.00

AC:

AN:

316

European-Non Finnish (NFE)

AF:

0.000191

AC:

AN:

68006

Other (OTH)

AF:

0.00

AC:

AN:

2086

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.475

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Genome Het

Variant carriers

<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:

0.000117

Hom.:

Bravo

AF:

0.0000907

ESP6500AA

AF:

0.00

AC:

ESP6500EA

AF:

0.000235

AC:

ExAC

AF:

0.0000842

AC:

EpiCase

AF:

0.000218

EpiControl

AF:

0.000415

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:7Benign:1Other:1

Revision: reviewed by expert panel

LINK: link

Submissions by phenotype

not provided

Uncertain:2Benign:1Other:1

Nov 19, 2024

GeneDx

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Identified in a patient with LQTS in published literature; however, this patient harbored an additional variant in the KCNH2 gene (PMID: 21164565); Identified in two cases of stillbirth in published literature (PMID: 30615648); Published functional studies suggest a damaging effect via decreased current density and prolonged duration of simulated left ventricular epicardial action potentials, but without affecting cell surface expression (PMID: 30571187, 21164565, 29532034); In silico analysis indicates that this missense variant does not alter protein structure/function; This variant is associated with the following publications: (PMID: 14661677, 21164565, 23861362, 22949429, 19841300, 30571187, 29532034, 29021305, 32797034, 22581653, 30615648) -

May 01, 2018

CeGaT Center for Human Genetics Tuebingen

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Cardiovascular Biomedical Research Unit, Royal Brompton & Harefield NHS Foundation Trust

Significance:not provided

Review Status:no classification provided

Collection Method:literature only

This variant has been reported in the following publications (PMID:14661677;PMID:19841300;PMID:21164565). -

Jun 24, 2013

Biesecker Lab/Clinical Genomics Section, National Institutes of Health

Significance:Likely benign

Review Status:criteria provided, single submitter

Collection Method:research

- -

Long QT syndrome 1

Uncertain:2

Jun 24, 2022

Victorian Clinical Genetics Services, Murdoch Childrens Research Institute

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Based on the classification scheme VCGS_Germline_v1.3.4, this variant is classified as VUS-3B. Following criteria are met: 0103 - Dominant negative, loss of function and gain of function are known mechanisms of disease in this gene. Gain of function variants result exclusively in short QT syndrome (MIM#609621), while dominant negative and loss of function variants can cause long QT syndrome (LQTS, MIM#192500), atrial fibrillation (MIM#607554) and Jervell and Lange-Nielsen syndrome (JLNS, MIM#220400) (OMIM, PMIDs: 19632626, 28438721). (I) 0108 - This gene is known to be associated with both recessive and dominant disease. JLNS is characterized by congenital, bilateral deafness and variable degrees of QT prolongation, and is the only condition caused by biallelic variants (PMID: 28438721). (I) 0112 - The condition associated with this gene has incomplete penetrance (OMIM, GeneReviews). (I) 0200 - Variant is predicted to result in a missense amino acid change from valine to isoleucine. (I) 0251 - This variant is heterozygous. (I) 0304 - Variant is present in gnomAD (v2 and v3) <0.01 for a condition (27 heterozygotes, 0 homozygotes). (SP) 0502 - Missense variant with conflicting in silico predictions and uninformative conservation. (I) 0604 - Variant is not located in an established domain, motif, hotspot or informative constraint region. (I) 0705 - No comparable missense variants have previous evidence for pathogenicity. (I) 0808 - Previous reports of pathogenicity for this variant are conflicting. This variant has been classified as a VUS by multiple clinical diagnostic laboratories and a benign variant based on its allele frequency being greater than published estimates for LQTS disease prevalence (ClinVar, PMID: 23861362). However, this variant has also been reported in two stillbirth cases and one individual with severe LQTS who carried an additional common polymorphism in KCNH2 (PMIDs: 30615648, 21164565). (I) 0905 - No published segregation evidence has been identified for this variant. (I) 1002 - This variant has moderate functional evidence supporting abnormal protein function. The mutant transcript expressed in both CHO-KI and HEK293T cells and assessed using patch clamp studies demonstrated normal surface trafficking levels but reduced peak current densities compared to the WT transcript (PMIDs: 21164565, 29532034). It should be noted that the same reduction in peak current density was also observed in CHO-KI cells carrying a KCNH2 common polymorphism (PMID: 21164565). (I) 1208 - Inheritance information for this variant is not currently available in this individual. (I) Legend: (SP) - Supporting pathogenic, (I) - Information, (SB) - Supporting benign -

Jul 01, 2025

ClinGen Potassium Channel Arrhythmia Variant Curation Expert Panel, ClinGen

Significance:Uncertain significance

Review Status:reviewed by expert panel

Collection Method:curation

NM_000218.3(KCNQ1):c.328G>A is a missense variant predicted to cause substitution of valine by isoleucine at amino acid 110 (p.Val110Ile). This variant is present in gnomAD v.4.1.0 at a maximum allele frequency of 0.00008307, with 98 alleles / 1,179,710 total alleles in the European (non-Finnish) population, which is higher than the ClinGen Potassium Channel Arrhythmia VCEP PM2_Supporting threshold of <0.00001, but lower than the BS1 threshold of >0.0004, so neither criterion is met. Functional studies have been performed on this variant (PMID: 21164565, 29532034, and 29021305) but do not meet VCEP criteria for PS3/BS3. The computational predictor REVEL gives a score of 0.562, which is below the ClinGen Potassium Channel Arrhythmia VCEP PP3 threshold of >0.75 but higher than the BP4 threshold of <0.25 and does not strongly predict a damaging effect on KCNQ1 function. The computational splicing predictor SpliceAI gives a score of 0.00, which is lower than the ClinGen Potassium Channel Arrhythmia VCEP PP3 threshold of greater than or equal to 0.2 and does not strongly predict a damaging effect on KCNQ1 splicing. In summary, this variant meets the criteria to be classified as a variant of uncertain significance for long QT syndrome 1 based on the ACMG/AMP criteria applied, as specified by the ClinGen Potassium Channel Arrhythmia VCEP: None. (VCEP specifications version 1.0.0; date of approval 03/04/2025). -

not specified

Uncertain:1

Jun 02, 2015

Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

The p.Val110Ile variant in KCNQ1 has not been previously reported in individuals with hearing loss or Jervell and Lange-Nielsen syndrome; however, it has been i dentified in one individual with long QT syndrome (Cordeiro 2010). This variant has also been identified in 8/55006 European chromosomes by the Exome Aggregatio n Consortium (ExAC, http://exac.broadinstitute.org; dbSNP rs199472677). In vitro functional studies provide some evidence that this variant may impact protein f unction (Cordeiro 2010); however, these types of assays may not accurately repre sent biological function. Computational prediction tools and conservation analy ses suggest that the p.Val110Ile variant may not impact the protein, though this information is not predictive enough to rule out pathogenicity. In summary, the clinical significance of the p.Val110Ile variant is uncertain. -

Long QT syndrome

Uncertain:1

Dec 06, 2023

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This sequence change replaces valine, which is neutral and non-polar, with isoleucine, which is neutral and non-polar, at codon 110 of the KCNQ1 protein (p.Val110Ile). This variant is present in population databases (rs199472677, gnomAD 0.01%). This missense change has been observed in individual(s) with long QT syndrome (PMID: 14661677, 19841300, 21164565). ClinVar contains an entry for this variant (Variation ID: 53034). Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) has been performed at Invitae for this missense variant, however the output from this modeling did not meet the statistical confidence thresholds required to predict the impact of this variant on KCNQ1 protein function. Experimental studies have shown that this missense change affects KCNQ1 function (PMID: 21164565, 29532034). 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

Feb 18, 2022

Ambry Genetics

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

The c.328G>A (p.V110I) alteration is located in exon 1 (coding exon 1) of the KCNQ1 gene. This alteration results from a G to A substitution at nucleotide position 328, causing the valine (V) at amino acid position 110 to be replaced by an isoleucine (I). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.15

CardioboostArm

Benign

0.0086

BayesDel_addAF

Uncertain

0.023

BayesDel_noAF

Uncertain

0.040

CADD

Uncertain

(source)

DANN

Uncertain

0.99

DEOGEN2

Benign

0.31

.;T

Eigen

Benign

-0.036

Eigen_PC

Benign

0.067

FATHMM_MKL

Pathogenic

0.98

LIST_S2

Uncertain

0.97

D;D

M_CAP

Pathogenic

0.76

MetaRNN

Uncertain

0.50

T;T

MetaSVM

Pathogenic

1.3

MutationAssessor

Benign

1.6

.;L

PhyloP100

6.9

PrimateAI

Pathogenic

0.84

PROVEAN

Benign

-0.36

N;N

REVEL

Uncertain

0.56

Sift

Benign

0.42

T;T

Sift4G

Benign

0.29

T;T

Polyphen

0.21

.;B

Vest4

0.28

MVP

0.93

MPC

0.95

ClinPred

0.20

GERP RS

3.0

PromoterAI

-0.0038

Neutral

(source)

Varity_R

0.13

gMVP

0.73

Mutation Taster

=30/70

disease causing

(source)

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

You must be logged in to view publications. This limit was set because tens of millions (!) of queries from AI bots are generated daily.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

Age Distribution

Age Distribution

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over