11-2445295-C-T

Variant names:

Variant summary

Our verdict is Uncertain significance. Variant got 0 ACMG points: 0P and 0B.

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 (★★).

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

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 links:

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ACMG classification

Classification made for transcript

Verdict is Uncertain_significance. Variant got 0 ACMG points.

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	UniProt
KCNQ1	ENST00000155840.12 link	c.197C>T	p.Ser66Phe	missense_variant	Exon 1 of 16	1	NM_000218.3	ENSP00000155840.2	P51787-1
KCNQ1	ENST00000646564.2 link	c.197C>T	p.Ser66Phe	missense_variant	Exon 1 of 11			ENSP00000495806.2	A0A2R8YEQ9
KCNQ1	ENST00000496887.7 link	c.24-88C>T		intron_variant	Intron 1 of 15	5		ENSP00000434560.2	E9PPZ0
KCNQ1	ENST00000345015.4 link	n.-27C>T		upstream_gene_variant		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

GnomAD4 exome

AF:

0.00000320

AC:

AN:

1250308

Hom.:

Cov.:

AF XY:

0.00000326

AC XY:

AN XY:

613288

show subpopulations

Gnomad4 AFR exome

AF:

0.0000387

Gnomad4 AMR exome

AF:

0.00

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.00

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

9.87e-7

Gnomad4 OTH exome

AF:

0.0000392

GnomAD4 genome

AF:

0.0000265

AC:

AN:

150696

Hom.:

Cov.:

AF XY:

0.0000407

AC XY:

AN XY:

73654

show subpopulations

Gnomad4 AFR

AF:

0.0000967

Gnomad4 AMR

AF:

0.00

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.00

Gnomad4 OTH

AF:

0.00

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

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Jan 30, 2025

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

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Feb 19, 2021

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

not provided, no classification provided

literature only

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

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

BayesDel_addAF

Pathogenic

0.19

BayesDel_noAF

Uncertain

0.040

CADD

Benign

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

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

Varity_R

0.079

gMVP

0.28

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

LitVar

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

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over