Genetic Variant KCNQ1:p.Ile274Val (chr11-2572885-A-G) – ACMG Classification: Uncertain_significance (4 pts)

Variant summary

Our verdict is Uncertain significance. The variant received 4 ACMG points: 5P and 1B. PM1PM5PP2BP6

The NM_000218.3(KCNQ1):c.820A>G(p.Ile274Val) variant causes a missense change. The variant allele was found at a frequency of 0.000199 in 1,613,666 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. I274N) has been classified as Likely pathogenic.

Frequency

Genomes: 𝑓 0.00012 ( 0 hom., cov: 33)

Exomes 𝑓: 0.00021 ( 0 hom. )

Consequence

KCNQ1
NM_000218.3 missense

Scores

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:1U:7B:4O:1

Conservation

PhyloP100: 6.90

Publications

16 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: G2P, Labcorp Genetics (formerly Invitae)
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 4 ACMG points.

PM1

In a hotspot region, there are 22 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 11 uncertain in NM_000218.3

PM5

Other missense variant is known to change same aminoacid residue: Variant chr11-2572886-T-A is described in ClinVar as Likely_pathogenic. ClinVar VariationId is 1711271.Status of the report is criteria_provided_single_submitter, 1 stars.

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.

BP6

Variant 11-2572885-A-G is Benign according to our data. Variant chr11-2572885-A-G is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 67109.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_000218.3. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein
KCNQ1	NM_000218.3	MANE Select	c.820A>G	p.Ile274Val	missense	Exon 6 of 16	NP_000209.2
KCNQ1	NM_001406836.1		c.820A>G	p.Ile274Val	missense	Exon 6 of 15	NP_001393765.1
KCNQ1	NM_001406837.1		c.550A>G	p.Ile184Val	missense	Exon 7 of 17	NP_001393766.1

Ensembl Transcripts

Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
KCNQ1	ENST00000155840.12	TSL:1 MANE Select	c.820A>G	p.Ile274Val	missense	Exon 6 of 16	ENSP00000155840.2	P51787-1
KCNQ1	ENST00000335475.6	TSL:1	c.439A>G	p.Ile147Val	missense	Exon 6 of 16	ENSP00000334497.5	P51787-2
KCNQ1	ENST00000910997.1		c.817A>G	p.Ile273Val	missense	Exon 6 of 16	ENSP00000581056.1

Frequencies

GnomAD3 genomes

AF:

0.000125

AC:

AN:

152214

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.000121

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:

0.000376

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.000147

Gnomad OTH

AF:

0.00

GnomAD2 exomes

AF:

0.000180

AC:

AN:

250462

AF XY:

0.000206

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:

0.000694

Gnomad NFE exome

AF:

0.000257

Gnomad OTH exome

AF:

0.000164

GnomAD4 exome

AF:

0.000207

AC:

302

AN:

1461452

Hom.:

Cov.:

AF XY:

0.000210

AC XY:

153

AN XY:

727044

show subpopulations

African (AFR)

AF:

0.000119

AC:

AN:

33480

American (AMR)

AF:

0.00

AC:

AN:

44716

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:

86258

European-Finnish (FIN)

AF:

0.000490

AC:

AN:

53024

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5768

European-Non Finnish (NFE)

AF:

0.000236

AC:

262

AN:

1111988

Other (OTH)

AF:

0.000166

AC:

AN:

60384

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.479

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:

0.000125

AC:

AN:

152214

Hom.:

Cov.:

AF XY:

0.000161

AC XY:

AN XY:

74378

show subpopulations

African (AFR)

AF:

0.000121

AC:

AN:

41462

American (AMR)

AF:

0.00

AC:

AN:

15278

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3472

East Asian (EAS)

AF:

0.00

AC:

AN:

5194

South Asian (SAS)

AF:

0.00

AC:

AN:

4824

European-Finnish (FIN)

AF:

0.000376

AC:

AN:

10632

Middle Eastern (MID)

AF:

0.00

AC:

AN:

316

European-Non Finnish (NFE)

AF:

0.000147

AC:

AN:

68034

Other (OTH)

AF:

0.00

AC:

AN:

2090

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.509

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:

0.0000730

Hom.:

Bravo

AF:

0.000110

ESP6500AA

AF:

0.00

AC:

ESP6500EA

AF:

0.000116

AC:

ExAC

AF:

0.000255

AC:

EpiCase

AF:

0.000109

EpiControl

AF:

0.000119

ClinVar

ClinVar submissions

Significance:Conflicting classifications of pathogenicity

Revision:criteria provided, conflicting classifications

View on ClinVar

Pathogenic

VUS

Benign

Condition

Long QT syndrome (2)

not provided (2)

Atrial fibrillation, familial, 3 (1)

Cardiac arrhythmia (1)

Cardiovascular phenotype (1)

Jervell and Lange-Nielsen syndrome 1 (1)

Long QT syndrome 1 (1)

not specified (1)

Short QT syndrome type 2 (1)

SUDDEN INFANT DEATH SYNDROME (1)

Congenital long QT syndrome (1)

Computational scores

Source: dbNSFP v4.9

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Uncertain

0.45

CardioboostArm

Uncertain

0.37

BayesDel_addAF

Pathogenic

0.31

BayesDel_noAF

Pathogenic

0.50

CADD

Pathogenic

(source)

DANN

Uncertain

1.0

DEOGEN2

Uncertain

0.79

Eigen

Uncertain

0.42

Eigen_PC

Uncertain

0.38

FATHMM_MKL

Uncertain

0.95

LIST_S2

Uncertain

0.95

M_CAP

Pathogenic

0.88

MetaRNN

Uncertain

0.49

MetaSVM

Pathogenic

1.1

MutationAssessor

Benign

0.93

PhyloP100

6.9

PrimateAI

Uncertain

0.78

PROVEAN

Benign

-0.98

REVEL

Pathogenic

0.85

Sift

Pathogenic

0.0

Sift4G

Uncertain

0.0030

Polyphen

0.89

Vest4

0.93

MVP

0.96

MPC

1.1

ClinPred

0.18

GERP RS

3.7

Varity_R

0.88

gMVP

0.95

Mutation Taster

=23/77

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

Variant Effect in Transcripts

RefSeq Transcripts

Ensembl Transcripts

Frequencies

Age Distribution

Age Distribution

ClinVar

Computational scores

Splicing

Publications

Other links and lift over