rs763462603

Positions:

• chr11-2570664-GTGGTCCGCCTC-G
• chr11-2570664-GTGGTCCGCCTC-GTGGTCCGCCTCTGGTCCGCCTC

Variant summary

Our verdict is Pathogenic. Variant got 18 ACMG points: 18P and 0B. PVS1 PM2 PP5_Very_Strong

The NM_000218.3(KCNQ1):​c.524_534delTCTGGTCCGCC​(p.Leu175fs) variant causes a frameshift change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000205 in 1,460,332 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Likely pathogenic (★★). Variant results in nonsense mediated mRNA decay.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.0000021 (0 hom.)
• Consequence: KCNQ1 NM_000218.3 frameshift
• Clinical Significance: Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:4
• Conservation: PhyloP100: 9.42

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 18 ACMG points.

• PVS1: Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 11-2570664-GTGGTCCGCCTC-G is Pathogenic according to our data. Variant chr11-2570664-GTGGTCCGCCTC-G is described in ClinVar as [Likely_pathogenic]. Clinvar id is 519537.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr11-2570664-GTGGTCCGCCTC-G is described in Lovd as [Pathogenic]. Variant chr11-2570664-GTGGTCCGCCTC-G is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
KCNQ1	NM_000218.3	c.524_534delTCTGGTCCGCC	p.Leu175fs	frameshift_variant	3/16	ENST00000155840.12	NP_000209.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
KCNQ1	ENST00000155840.12	c.524_534delTCTGGTCCGCC	p.Leu175fs	frameshift_variant	3/16	1	NM_000218.3	ENSP00000155840.2
KCNQ1	ENST00000335475.6	c.143_153delTCTGGTCCGCC	p.Leu48fs	frameshift_variant	3/16	1		ENSP00000334497.5
KCNQ1	ENST00000496887.7	c.263_273delTCTGGTCCGCC	p.Leu88fs	frameshift_variant	4/16	5		ENSP00000434560.2
KCNQ1	ENST00000646564.2	c.478-12761_478-12751delTCTGGTCCGCC		intron_variant				ENSP00000495806.2

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 0.00000205 AC: 3 AN: 1460332 Hom.: 0 AF XY: 0.00 AC XY: 0 AN XY: 726560

Gnomad4 AFR exome AF: 0.00

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: 0.00000270

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 33

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:4

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Long QT syndrome Pathogenic:2

Pathogenic, criteria provided, single submitter	clinical testing	Labcorp Genetics (formerly Invitae), Labcorp	Oct 15, 2023	This sequence change creates a premature translational stop signal (p.Leu175Argfs*106) 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 not present in population databases (gnomAD no frequency). This premature translational stop signal has been observed in individual(s) with long QT syndrome (PMID: 19716085). ClinVar contains an entry for this variant (Variation ID: 519537). For these reasons, this variant has been classified as Pathogenic. -
Pathogenic, criteria provided, single submitter	clinical testing	All of Us Research Program, National Institutes of Health	Mar 14, 2024	This variant deletes 11 nucleotides in exon 3 of the cytoplasmic linker domain of the KCNQ1 gene, creating a frameshift and premature translation stop signal. This variant is expected to result in an absent or non-functional protein product. This variant has been reported in an individual suspected of having long QT syndrome (PMID: 19716085) and in another individual suspected of having inherited arrhythmia (PMID: 31696929). This variant has not been identified 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. -

not provided Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

GeneDx

Jul 21, 2020

Identified in an individual referred for LQTS testing in published literature (Kapplinger et al., 2009); Not observed in large population cohorts (Lek et al., 2016); Frameshift 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; This variant is associated with the following publications: (PMID: 19716085) -

Cardiovascular phenotype Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Ambry Genetics

Nov 17, 2017

The c.524_534del11 pathogenic mutation, located in coding exon 3 of the KCNQ1 gene, results from a deletion of 11 nucleotides at nucleotide positions 524 to 534, causing a translational frameshift with a predicted alternate stop codon (p.L175Rfs*106). In a study of long QT syndrome clinical genetic testing, this alteration (also referred to as R174fs+105X) was reported in one patient; however, clinical details were limited (Kapplinger JD et al. Heart Rhythm, 2009 Sep;6:1297-303). In addition, 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

Splicing

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

LitVar

Other links and lift over

dbSNP: rs763462603; hg19: chr11-2591894;