NM_000218.3:c.197C>T

Variant names:

Variant summary

Our verdict is Uncertain significance. The variant received 1 ACMG points: 1P and 0B. PP2

The NM_000218.3(KCNQ1):c.197C>T(p.Ser66Phe) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000571 in 1,401,004 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. S66Y) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.000027 ( 0 hom., cov: 32)

Exomes 𝑓: 0.0000032 ( 0 hom. )

Consequence

KCNQ1
NM_000218.3 missense

Scores

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:2O:1

Conservation

PhyloP100: 0.0790

Publications

5 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 1 ACMG points.

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.197C>T	p.Ser66Phe	missense_variant	Exon 1 of 16	ENST00000155840.12	NP_000209.2	P51787-1Q96AI9
KCNQ1	NM_001406836.1 link	c.197C>T	p.Ser66Phe	missense_variant	Exon 1 of 15		NP_001393765.1
KCNQ1	NM_001406838.1 link	c.197C>T	p.Ser66Phe	missense_variant	Exon 1 of 11		NP_001393767.1
KCNQ1	NM_001406837.1 link	c.-166C>T		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.197C>T	p.Ser66Phe	missense_variant	Exon 1 of 16	1	NM_000218.3	ENSP00000155840.2		P51787-1

Frequencies

GnomAD3 genomes

AF:

0.0000266

AC:

AN:

150588

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0000970

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:

0.00

AC:

AN:

60432

AF XY:

0.00

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:

0.00

Gnomad NFE exome

AF:

0.00

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.00000320

AC:

AN:

1250308

Hom.:

Cov.:

AF XY:

0.00000326

AC XY:

AN XY:

613288

show subpopulations

African (AFR)

AF:

0.0000387

AC:

AN:

25842

American (AMR)

AF:

0.00

AC:

AN:

20856

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

19584

East Asian (EAS)

AF:

0.00

AC:

AN:

28762

South Asian (SAS)

AF:

0.00

AC:

AN:

58188

European-Finnish (FIN)

AF:

0.00

AC:

AN:

28828

Middle Eastern (MID)

AF:

0.00

AC:

AN:

3928

European-Non Finnish (NFE)

AF:

9.87e-7

AC:

AN:

1013296

Other (OTH)

AF:

0.0000392

AC:

AN:

51024

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.438

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:

0.0000265

AC:

AN:

150696

Hom.:

Cov.:

AF XY:

0.0000407

AC XY:

AN XY:

73654

show subpopulations

African (AFR)

AF:

0.0000967

AC:

AN:

41354

American (AMR)

AF:

0.00

AC:

AN:

15128

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3462

East Asian (EAS)

AF:

0.00

AC:

AN:

5146

South Asian (SAS)

AF:

0.00

AC:

AN:

4820

European-Finnish (FIN)

AF:

0.00

AC:

AN:

9928

Middle Eastern (MID)

AF:

0.00

AC:

AN:

292

European-Non Finnish (NFE)

AF:

0.00

AC:

AN:

67570

Other (OTH)

AF:

0.00

AC:

AN:

2084

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.463

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:

0.00

Hom.:

Bravo

AF:

0.0000302

ExAC

AF:

0.0000346

AC:

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2Other:1

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Long QT syndrome

Uncertain:1

Jan 30, 2025

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This sequence change replaces serine, which is neutral and polar, with phenylalanine, which is neutral and non-polar, at codon 66 of the KCNQ1 protein (p.Ser66Phe). This variant is not present in population databases (gnomAD no frequency). This missense change has been observed in individual(s) with clinical features of long QT syndrome (PMID: 19716085). ClinVar contains an entry for this variant (Variation ID: 67063). Invitae Evidence Modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) indicates that this missense variant is not expected to disrupt KCNQ1 protein function with a negative predictive value of 95%. Experimental studies have shown that this missense change affects KCNQ1 function (PMID: 34930020). 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 19, 2021

Ambry Genetics

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

The c.197C>T (p.S66F) alteration is located in exon 1 (coding exon 1) of the KCNQ1 gene. This alteration results from a C to T substitution at nucleotide position 197, causing the serine (S) at amino acid position 66 to be replaced by a phenylalanine (F). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

Congenital long QT syndrome

Other:1

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 as associated with Long QT syndrome in the following publications (PMID:19716085). This is a literature report, and does not necessarily reflect the clinical interpretation of the Imperial College / Royal Brompton Cardiovascular Genetics laboratory. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.13

CardioboostArm

Uncertain

0.41

BayesDel_addAF

Pathogenic

0.19

BayesDel_noAF

Uncertain

0.040

CADD

Benign

(source)

DANN

Benign

0.96

DEOGEN2

Uncertain

0.47

Eigen

Benign

-0.77

Eigen_PC

Benign

-0.83

FATHMM_MKL

Benign

0.059

LIST_S2

Benign

0.44

M_CAP

Pathogenic

0.89

MetaRNN

Uncertain

0.52

MetaSVM

Uncertain

0.64

MutationAssessor

Benign

1.0

PhyloP100

0.079

PrimateAI

Pathogenic

0.84

PROVEAN

Benign

-2.0

REVEL

Pathogenic

0.65

Sift

Uncertain

0.0090

Sift4G

Uncertain

0.018

Polyphen

0.085

Vest4

0.24

MutPred

0.75

Loss of glycosylation at S66 (P = 4e-04);

MVP

0.94

MPC

1.5

ClinPred

0.21

GERP RS

2.0

PromoterAI

-0.0078

Neutral

(source)

Varity_R

0.079

gMVP

0.28

Mutation Taster

=28/72

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