11-2572979-G-A

Position:

• chr11-2572979-G-A

Variant summary

Our verdict is Pathogenic. Variant got 16 ACMG points: 16P and 0B. PVS1 PP5_Very_Strong

The NM_000218.3(KCNQ1):​c.914G>A​(p.Trp305Ter) 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
• Clinical Significance: Pathogenic criteria provided, multiple submitters, no conflicts P:9
• Conservation: PhyloP100: 9.36

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]

ACMG classification

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/exons	MANE	Protein	UniProt
KCNQ1	NM_000218.3	c.914G>A	p.Trp305Ter	stop_gained	6/16	ENST00000155840.12	NP_000209.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
KCNQ1	ENST00000155840.12	c.914G>A	p.Trp305Ter	stop_gained	6/16	1	NM_000218.3	ENSP00000155840	P1
KCNQ1	ENST00000335475.6	c.533G>A	p.Trp178Ter	stop_gained	6/16	1		ENSP00000334497
KCNQ1	ENST00000496887.7	c.653G>A	p.Trp218Ter	stop_gained	7/16	5		ENSP00000434560
KCNQ1	ENST00000646564.2	c.478-10456G>A		intron_variant				ENSP00000495806

Frequencies

GnomAD3 genomes AF: 0.0000131 AC: 2 AN: 152226 Hom.: 0 Cov.: 33

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: 4 AN: 249180 Hom.: 0 AF XY: 0.0000148 AC XY: 2 AN XY: 135116

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: 5 AN: 1460482 Hom.: 0 Cov.: 32 AF XY: 0.00000551 AC XY: 4 AN XY: 726452

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: 2 AN: 152226 Hom.: 0 Cov.: 33 AF XY: 0.0000134 AC XY: 1 AN XY: 74356

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.: 0

Bravo AF: 0.00000756

ExAC AF: 0.0000165 AC: 2

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:9

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

not provided Pathogenic:2

Pathogenic, criteria provided, single submitter	clinical testing	GeneDx	Jul 18, 2024	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) -
Pathogenic, criteria provided, single submitter	clinical testing	AiLife Diagnostics, AiLife Diagnostics	Jan 12, 2022	- -

Long QT syndrome Pathogenic:2

Pathogenic, criteria provided, single submitter	clinical testing	All of Us Research Program, National Institutes of Health	Jan 08, 2024	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. -
Pathogenic, criteria provided, single submitter	clinical testing	Labcorp Genetics (formerly Invitae), Labcorp	Oct 17, 2022	For these reasons, this variant has been classified as Pathogenic. Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may create or strengthen a splice site. ClinVar contains an entry for this variant (Variation ID: 53124). This premature translational stop signal has been observed in individuals with LQTS (PMID: 12702160; Invitae). It has also been observed to segregate with disease in related individuals. This variant is present in population databases (rs120074186, gnomAD 0.008%). 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). -

Cardiac arrhythmia Pathogenic:2

Pathogenic, criteria provided, single submitter	clinical testing	Women's Health and Genetics/Laboratory Corporation of America, LabCorp	Jul 08, 2019	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. -
Pathogenic, criteria provided, single submitter	clinical testing	Color Diagnostics, LLC DBA Color Health	Dec 19, 2023	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. -

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

Pathogenic, criteria provided, single submitter

clinical testing

Fulgent Genetics, Fulgent Genetics

Apr 29, 2022

- -

Congenital long QT syndrome Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine

Jan 06, 2021

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

Pathogenic, criteria provided, single submitter

clinical testing

Ambry Genetics

Dec 03, 2021

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	D
BayesDel_noAF	Pathogenic	0.65
CADD	Pathogenic	55
DANN	Uncertain	1.0
Eigen	Pathogenic	1.1
Eigen_PC	Pathogenic	0.88
FATHMM_MKL	Pathogenic	0.98	D
MutationTaster	Benign	1.0	A;A
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

Other links and lift over

dbSNP: rs120074186; hg19: chr11-2594209;