NM_000218.3:c.914G>A

Variant names:

Variant summary

Our verdict is Pathogenic. Variant got 16 ACMG points: 16P and 0B. PVS1PP5_Very_Strong

The NM_000218.3(KCNQ1):c.914G>A(p.Trp305*) variant causes a stop gained change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000434 in 1,612,708 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Pathogenic (★★). Variant results in nonsense mediated mRNA decay.

Frequency

Genomes: 𝑓 0.000013 ( 0 hom., cov: 33)

Exomes 𝑓: 0.0000034 ( 0 hom. )

Consequence

KCNQ1
NM_000218.3 stop_gained

Scores

Clinical Significance

Pathogenic criteria provided, multiple submitters, no conflicts P:9

Conservation

PhyloP100: 9.36

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:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Pathogenic. Variant got 16 ACMG points.

PVS1

Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.

PP5

Variant 11-2572979-G-A is Pathogenic according to our data. Variant chr11-2572979-G-A is described in ClinVar as [Pathogenic]. Clinvar id is 53124.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr11-2572979-G-A is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
KCNQ1	NM_000218.3 link	c.914G>A	p.Trp305*	stop_gained	Exon 6 of 16	ENST00000155840.12	NP_000209.2	P51787-1Q96AI9

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	UniProt
KCNQ1	ENST00000155840.12 link	c.914G>A	p.Trp305*	stop_gained	Exon 6 of 16	1	NM_000218.3	ENSP00000155840.2	P51787-1
KCNQ1	ENST00000335475.6 link	c.533G>A	p.Trp178*	stop_gained	Exon 6 of 16	1		ENSP00000334497.5	P51787-2
KCNQ1	ENST00000496887.7 link	c.653G>A	p.Trp218*	stop_gained	Exon 7 of 16	5		ENSP00000434560.2	E9PPZ0
KCNQ1	ENST00000646564.2 link	c.478-10456G>A		intron_variant	Intron 2 of 10			ENSP00000495806.2	A0A2R8YEQ9

Frequencies

GnomAD3 genomes

AF:

0.0000131

AC:

AN:

152226

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0000241

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:

0.0000147

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.0000161

AC:

AN:

249180

Hom.:

AF XY:

0.0000148

AC XY:

AN XY:

135116

show subpopulations

Gnomad AFR exome

AF:

0.0000623

Gnomad AMR exome

AF:

0.0000580

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad SAS exome

AF:

0.0000327

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.00000342

AC:

AN:

1460482

Hom.:

Cov.:

AF XY:

0.00000551

AC XY:

AN XY:

726452

show subpopulations

Gnomad4 AFR exome

AF:

0.0000896

Gnomad4 AMR exome

AF:

0.00

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.0000116

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.00

Gnomad4 OTH exome

AF:

0.0000166

GnomAD4 genome

AF:

0.0000131

AC:

AN:

152226

Hom.:

Cov.:

AF XY:

0.0000134

AC XY:

AN XY:

74356

show subpopulations

Gnomad4 AFR

AF:

0.0000241

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:

0.0000147

Gnomad4 OTH

AF:

0.00

Alfa

AF:

0.0000712

Hom.:

Bravo

AF:

0.00000756

ExAC

AF:

0.0000165

AC:

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:9

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

not provided

Pathogenic:2

Jul 18, 2024

GeneDx

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Reported in one individual with drug induced Torsades de Pointes (PMID: 24223155); Nonsense variant predicted to result in protein truncation or nonsense mediated decay in a gene for which loss of function is a known mechanism of disease; Not observed at significant frequency in large population cohorts (gnomAD); This variant is associated with the following publications: (PMID: 19862833, 25525159, 19716085, 12702160, 19841298, 29876285, 31447099, 23631430, 23995044, 30930557, 24692356, 23124029, 24223155) -

Jan 12, 2022

AiLife Diagnostics, AiLife Diagnostics

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Long QT syndrome

Pathogenic:2

Sep 25, 2024

All of Us Research Program, National Institutes of Health

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This variant changes 1 nucleotide in exon 6 of the KCNQ1 gene, creating a premature translation stop signal. This variant is expected to result in an absent or non-functional protein product. To our knowledge, functional studies have not been reported for this variant. This variant has been reported in one individual with sudden death and three individuals with long QT syndrome in one family (PMID: 12702160). This variant has been identified in 5/280572 chromosomes in the general population by the Genome Aggregation Database (gnomAD). Loss of KCNQ1 function is a known mechanism of disease (clinicalgenome.org). Based on the available evidence, this variant is classified as Pathogenic. -

Dec 25, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change creates a premature translational stop signal (p.Trp305*) in the KCNQ1 gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in KCNQ1 are known to be pathogenic (PMID: 9323054, 19862833). This variant is present in population databases (rs120074186, gnomAD 0.008%). This premature translational stop signal has been observed in individuals with LQTS (PMID: 12702160; internal data). It has also been observed to segregate with disease in related individuals. ClinVar contains an entry for this variant (Variation ID: 53124). For these reasons, this variant has been classified as Pathogenic. -

Cardiac arrhythmia

Pathogenic:2

Dec 19, 2023

Color Diagnostics, LLC DBA Color Health

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This variant changes 1 nucleotide in exon 6 of the KCNQ1 gene, creating a premature translation stop signal. This variant is expected to result in an absent or non-functional protein product. This variant has been shown to segregate with long QT syndrome in three related individuals in a family (PMID: 12702160). This variant has been identified in 5/280572 chromosomes in the general population by the Genome Aggregation Database (gnomAD). Loss of KCNQ1 function is a known mechanism of disease (clinicalgenome.org). Based on the available evidence, this variant is classified as Pathogenic. -

Jul 08, 2019

Women's Health and Genetics/Laboratory Corporation of America, LabCorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Variant summary: KCNQ1 c.914G>A (p.Trp305X) results in a premature termination codon, predicted to cause a truncation of the encoded protein or absence of the protein due to nonsense mediated decay, which are commonly known mechanisms for disease. Truncations downstream of this position have been classified as pathogenic by our laboratory. The variant allele was found at a frequency of 1.6e-05 in 249180 control chromosomes (gnomAD). c.914G>A has been reported in the literature in multiple individuals affected with Long QT Syndrome (Chen_2003, Schwartz_2009, Cuneo_2013, Lieve_2013) and drug-induced Torsades de Pointes (diTdP) (Behr_2013). These data indicate that the variant is very likely to be associated with disease. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. Three ClinVar submissions (evaluation after 2014) cite the variant as pathogenic. Based on the evidence outlined above, the variant was classified as pathogenic. -

Beckwith-Wiedemann syndrome;C1837014:Atrial fibrillation, familial, 3;C1865019:Short QT syndrome type 2;C4551509:Jervell and Lange-Nielsen syndrome 1;C4551647:Long QT syndrome 1

Pathogenic:1

Apr 29, 2022

Fulgent Genetics, Fulgent Genetics

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Congenital long QT syndrome

Pathogenic:1

Jan 06, 2021

Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The p.Trp305X variant in KCNQ1 has been reported in at least 1 individual with long QT syndrome (LQTS) and segregated with disease in at least 3 affected relatives (Chen et al. 2003). It has also been reported by other clinical laboratories in ClinVar (Variation ID 53124) and has been identified in 0.008% (2/24762) of African chromosomes by gnomAD (http://gnomad.broadinstitute.org). This nonsense variant leads to a premature termination codon at position 305, which is predicted to lead to a truncated or absent protein. Loss-of-function variants in KCNQ1 are associated with LQTS (also known as Romano-Ward syndrome) in the heterozygous state and with Jervell and Lange-Nielsen syndrome (JLNS) in the compound heterozygous or homozygous state. In summary, this variant meets criteria to be classified as pathogenic for LQTS in an autosomal dominant manner based upon segregation studies, very low frequency in the general population, and predicted impact to the protein. ACMG/AMP criteria applied: PVS1, PM2_Supporting, PP1_Supporting. -

Cardiovascular phenotype

Pathogenic:1

Dec 03, 2021

Ambry Genetics

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The p.W305* pathogenic mutation (also known as c.914G>A), located in coding exon 6 of the KCNQ1 gene, results from a G to A substitution at nucleotide position 914. This changes the amino acid from a tryptophan to a stop codon within coding exon 6. This alteration has been reported in multiple individuals with long QT syndrome (Chen S. et al. Clin. Genet. 2003;63(4):273-82; Kapplinger JD et al. Heart Rhythm. 2009;6(9):1297-303; Schwartz PJ et al. Circulation 2009;120(18):1761-7; Lieve KV et al. Genet Test Mol Biomarkers, 2013 Jul;17:553-61). In addition to the clinical data presented in the literature, this alteration is expected to result in loss of function by premature protein truncation or nonsense-mediated mRNA decay. As such, this alteration is interpreted as a disease-causing mutation. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

BayesDel_addAF

Pathogenic

0.49

BayesDel_noAF

Pathogenic

0.65

CADD

Pathogenic

DANN

Uncertain

1.0

Eigen

Pathogenic

1.1

Eigen_PC

Pathogenic

0.88

FATHMM_MKL

Pathogenic

0.98

Vest4

0.96

GERP RS

3.9

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.39

Details are displayed if max score is > 0.2

DS_DG_spliceai

0.39

Position offset: -3

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