rs397508128

Variant names:

• chr11-2572889-TCTC-T
• rs397508127
• NM_000218.3:c.828_830delCTC

Variant summary

Our verdict is Pathogenic. Variant got 13 ACMG points: 13P and 0B. PM1 PM2 PM4_Supporting PP5_Very_Strong

The NM_000218.3(KCNQ1):​c.828_830delCTC​(p.Ser277del) variant causes a disruptive inframe deletion change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. Variant has been reported in ClinVar as Pathogenic (★★).

• Frequency: Genomes: not found (cov: 33)
• Consequence: KCNQ1 NM_000218.3 disruptive_inframe_deletion
• Clinical Significance: Pathogenic criteria provided, multiple submitters, no conflicts P:8
• Conservation: PhyloP100: 7.41

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 13 ACMG points.

• PM1: In a helix (size 25) in uniprot entity KCNQ1_HUMAN there are 38 pathogenic changes around while only 0 benign (100%) in NM_000218.3
• PM2: Very rare variant in population databases, with high coverage
• PM4: Nonframeshift variant in NON repetitive region in NM_000218.3. Strenght limited to Supporting due to length of the change: 1aa.
• PP5: Variant 11-2572889-TCTC-T is Pathogenic according to our data. Variant chr11-2572889-TCTC-T is described in ClinVar as [Pathogenic]. Clinvar id is 53114.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr11-2572889-TCTC-T is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
KCNQ1	NM_000218.3	c.828_830delCTC	p.Ser277del	disruptive_inframe_deletion	Exon 6 of 16	ENST00000155840.12	NP_000209.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
KCNQ1	ENST00000155840.12	c.828_830delCTC	p.Ser277del	disruptive_inframe_deletion	Exon 6 of 16	1	NM_000218.3	ENSP00000155840.2
KCNQ1	ENST00000335475.6	c.447_449delCTC	p.Ser150del	disruptive_inframe_deletion	Exon 6 of 16	1		ENSP00000334497.5
KCNQ1	ENST00000496887.7	c.567_569delCTC	p.Ser190del	disruptive_inframe_deletion	Exon 7 of 16	5		ENSP00000434560.2
KCNQ1	ENST00000646564.2	c.478-10542_478-10540delCTC		intron_variant	Intron 2 of 10			ENSP00000495806.2

Frequencies

GnomAD3 genomes Cov.: 33

We have no GnomAD4 exomes data on this position. Probably position not covered by the project.

GnomAD4 genome Cov.: 33

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:8

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Long QT syndrome 1 Pathogenic:3

Feb 15, 2018

Center For Human Genetics And Laboratory Diagnostics, Dr. Klein, Dr. Rost And Colleagues

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Jul 02, 2020

Victorian Clinical Genetics Services, Murdoch Childrens Research Institute

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Based on the classification scheme VCGS_Germline_v1.3.3, this variant is classified as 5-Pathogenic. Following criteria are met: 0103 - Dominant negative, loss of function and gain of function are known mechanisms of disease in this gene. Gain of function mutations result exclusively in Short QT syndrome (SQTS), while dominant negative and loss of function mutations can cause Long QT syndrome (LQTS), atrial fibrillation (AF) and Jervell and Lange-Nielson syndrome (JLNS) (OMIM, PMID: 19632626, PMID: 28438721). (I) 0108 - This gene is known to be associated with both recessive and dominant disease. JLNS is a more severe form of LQTS, and is the only condition caused by biallelic pathogenic variants (PMID: 28438721). (I) 0112 - The condition associated with this gene has incomplete penetrance (GeneReviews, OMIM). (I) 0213 - In-frame deletion in a non-repetitive region that has high conservation. (SP) 0251 - This variant is heterozygous. (I) 0301 - Variant is absent from gnomAD (both v2 and v3). (SP) 0600 - Variant is located in the annotated S5 transmembrane domain (PMID: 15194462). (I) 0801 - This variant has strong previous evidence of pathogenicity in unrelated individuals. This variant has been reported in individuals with LQTS and in compound heterozygous individuals with JLNS (PMIDs: 15194462, 15176425, 16414944, 20890437, 22539601, 27485560). (SP) 1002 - This variant has moderate functional evidence supporting abnormal protein function. Transfected mutant protein in COS-7 cells demonstrated loss of K+ currents using the patch clamp technique and retention in endoplasmic reticulum (ER) compared to wild type protein. Moreover, co-transfection of mutant and wild type proteins resulted in intermediate K+ currents (PMIDs: 15194462). (SP) 1208 - Inheritance information for this variant is not currently available in this individual. (I) Legend: (SP) - Supporting pathogenic, (I) - Information, (SB) - Supporting benign -

Jan 01, 2013

Institute of Medical Genetics and Genomics, Sir Ganga Ram Hospital

Significance: Pathogenic

Review Status: no assertion criteria provided

Collection Method: research

- -

not provided Pathogenic:3

Dec 01, 2020

CeGaT Center for Human Genetics Tuebingen

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Oct 16, 2020

GeneDx

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Not observed in large population cohorts (Lek et al., 2016); In silico analysis supports a deleterious effect on protein structure/function; Published functional studies demonstrate this variant results in reduced potassium channel activity (reported as S276del due to alternate nomenclature; Gouas et al., 2004); This variant is associated with the following publications: (PMID: 20890437, 22539601, 15194462, 27485560, 15176425, 16414944, 32048431, 31737537) -

Jun 17, 2021

Institute of Medical Genetics and Applied Genomics, University Hospital Tübingen

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

not specified Pathogenic:1

Nov 06, 2015

Clinical Molecular Genetics Laboratory, Johns Hopkins All Children's Hospital

Significance: Pathogenic

Review Status: no assertion criteria provided

Collection Method: clinical testing

- -

Long QT syndrome Pathogenic:1

Oct 19, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This variant, c.828_830del, results in the deletion of 1 amino acid(s) of the KCNQ1 protein (p.Ser277del), but otherwise preserves the integrity of the reading frame. This variant is not present in population databases (gnomAD no frequency). This variant has been observed in individuals with Jervell and Lange-Nielsen syndrome and/or Long QT syndrome (PMID: 20890437, 22539601; internal data). This variant is also known as p.Ser276del. ClinVar contains an entry for this variant (Variation ID: 53114). Algorithms developed to predict the effect of variants on gene product structure and function are not available or were not evaluated for this variant. Experimental studies have shown that this variant affects KCNQ1 function (PMID: 15194462). This variant disrupts the p.Ser277 amino acid residue in KCNQ1. Other variant(s) that disrupt this residue have been determined to be pathogenic (PMID: 12442276, 16414944, 19716085, 21241800, 21895724, 23130128). This suggests that this residue is clinically significant, and that variants that disrupt this residue are likely to be disease-causing. For these reasons, this variant has been classified as Pathogenic. -

Computational scores

Source: dbNSFP v4.3

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

Other links and lift over

dbSNP: rs397508127; hg19: chr11-2594119;