11-2572954-G-C

Variant names:

Variant summary

Our verdict is Uncertain significance. The variant received 5 ACMG points: 5P and 0B. PM1PM2PP2

The NM_000218.3(KCNQ1):c.889G>C(p.Gly297Arg) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,442 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. G297S) has been classified as Uncertain significance.

Frequency

Genomes: not found (cov: 33)

Exomes 𝑓: 6.8e-7 ( 0 hom. )

Consequence

KCNQ1
NM_000218.3 missense

Scores

Clinical Significance

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

Conservation

PhyloP100: 1.73

Publications

4 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 5 ACMG points.

PM1

In a hotspot region, there are 16 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 13 uncertain in NM_000218.3

PM2

Very rare variant in population databases, with high coverage;

PP2

Missense variant in the gene, where a lot of missense mutations are associated with disease in ClinVar. The gene has 212 curated pathogenic missense variants (we use a threshold of 10). The gene has 12 curated benign missense variants. Gene score misZ: 1.8321 (below the threshold of 3.09). Trascript score misZ: 0.90233 (below the threshold of 3.09). GenCC associations: The gene is linked to short QT syndrome type 2, long QT syndrome 1, Jervell and Lange-Nielsen syndrome 1, long QT syndrome, short QT syndrome, Jervell and Lange-Nielsen syndrome, hypertrophic cardiomyopathy, familial atrial fibrillation, atrial fibrillation, familial, 3.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
KCNQ1	NM_000218.3 link	c.889G>C	p.Gly297Arg	missense_variant	Exon 6 of 16	ENST00000155840.12	NP_000209.2	P51787-1Q96AI9

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
KCNQ1	ENST00000155840.12 link	c.889G>C	p.Gly297Arg	missense_variant	Exon 6 of 16	1	NM_000218.3	ENSP00000155840.2		P51787-1

Frequencies

GnomAD3 genomes

Cov.:

GnomAD2 exomes

AF:

0.00000400

AC:

AN:

250094

AF XY:

0.00

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.0000290

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:

6.84e-7

AC:

AN:

1461442

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

727022

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

33480

American (AMR)

AF:

0.0000224

AC:

AN:

44710

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26134

East Asian (EAS)

AF:

0.00

AC:

AN:

39700

South Asian (SAS)

AF:

0.00

AC:

AN:

86250

European-Finnish (FIN)

AF:

0.00

AC:

AN:

53042

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5768

European-Non Finnish (NFE)

AF:

0.00

AC:

AN:

1111972

Other (OTH)

AF:

0.00

AC:

AN:

60386

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

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

Cov.:

Alfa

AF:

0.00

Hom.:

Bravo

AF:

0.00000378

ExAC

AF:

0.00000824

AC:

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:3

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Long QT syndrome

Uncertain:2

Oct 01, 2021

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

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. Algorithms developed to predict the effect of missense changes on protein structure and function (SIFT, PolyPhen-2, Align-GVGD) all suggest that this variant is likely to be tolerated. This variant has not been reported in the literature in individuals affected with KCNQ1-related conditions. This variant is present in population databases (rs34320941, ExAC 0.009%). This sequence change replaces glycine with arginine at codon 297 of the KCNQ1 protein (p.Gly297Arg). The glycine residue is highly conserved and there is a moderate physicochemical difference between glycine and arginine. -

Aug 15, 2023

All of Us Research Program, National Institutes of Health

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This missense variant replaces glycine with arginine at codon 297 of the KCNQ1 protein. Computational prediction is inconclusive regarding the impact of this variant on protein structure and function (internally defined REVEL score threshold 0.5 < inconclusive < 0.7, PMID: 27666373). To our knowledge, functional studies have not been reported for this variant. This variant has not been reported in individuals affected with KCNQ1-related disorders in the literature. This variant has been identified in 1/250094 chromosomes in the general population by the Genome Aggregation Database (gnomAD). The available evidence is insufficient to determine the role of this variant in disease conclusively. Therefore, this variant is classified as a Variant of Uncertain Significance. -

Cardiovascular phenotype

Uncertain:1

May 06, 2021

Ambry Genetics

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

The p.G297R variant (also known as c.889G>C), located in coding exon 6 of the KCNQ1 gene, results from a G to C substitution at nucleotide position 889. The glycine at codon 297 is replaced by arginine, an amino acid with dissimilar properties, and is located in the transmembrane-spanning S5/pore region of the protein. This amino acid position is well conserved in available vertebrate species. In addition, the in silico prediction for this alteration is inconclusive. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.20

CardioboostArm

Benign

0.0070

BayesDel_addAF

Pathogenic

0.19

BayesDel_noAF

Uncertain

0.11

CADD

Uncertain

(source)

DANN

Benign

0.96

DEOGEN2

Pathogenic

0.83

D;.

Eigen

Benign

-0.67

Eigen_PC

Benign

-0.52

FATHMM_MKL

Uncertain

0.79

LIST_S2

Uncertain

0.97

D;D

M_CAP

Pathogenic

0.50

MetaRNN

Uncertain

0.56

D;D

MetaSVM

Uncertain

0.17

MutationAssessor

Benign

0.42

N;.

PhyloP100

1.7

PrimateAI

Uncertain

0.63

PROVEAN

Benign

-1.4

N;N

REVEL

Uncertain

0.62

Sift

Benign

0.14

T;T

Sift4G

Benign

0.33

T;T

Polyphen

0.21

B;B

Vest4

0.53

MutPred

0.58

Gain of methylation at G297 (P = 0.047);.;

MVP

0.90

MPC

0.54

ClinPred

0.16

GERP RS

3.0

Varity_R

0.47

gMVP

0.99

Mutation Taster

=18/82

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

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Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

Age Distribution

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over