11-2572905-G-T

Variant names:

• chr11-2572905-G-T
• rs1554893236
• NM_000218.3:c.840G>T

Variant summary

Our verdict is Likely benign. The variant received -2 ACMG points: 0P and 2B. BP4 BP7

This summary comes from the ClinGen Evidence Repository: NM_000218.3(KCNQ1):c.840G>T (p.Val280=) is a synonymous variant in exon 6. This variant is present in gnomAD v.4.1.0 at a maximum allele frequency of 0.00001610, with 19 alleles out of 1,180,028 total alleles in the European (non-Finnish) population, which is higher than the ClinGen Potassium Channel Arrhythmia VCEP PM2_Supporting threshold of <0.00001, but lower than the BS1 threshold of >0.0004, so neither criterion is met. The computational splicing predictor SpliceAI gives this silent variant a delta score of 0.06 for acceptor gain which is below the ClinGen Potassium Channel Arrhythmia VCEP BP7 threshold of <0.2 and does not strongly predict a splicing defect (BP4). In addition, the conservation tool PhyloP gives this variant a score of 0.275, which is below the Potassium Channel Arrhythmia VCEP BP7 threshold of <2.0 and indicates a low level of evolutionary conservation at this site (BP7). In summary, this variant meets the criteria to be classified as likely benign for long QT syndrome 1 based on the ACMG/AMP criteria applied, as specified by the ClinGen Potassium Channel Arrhythmia VCEP: BP4 and BP7. (VCEP specifications version 1.0.0; date of approval 03/04/2025). LINK:https://erepo.genome.network/evrepo/ui/classification/CA472038164/MONDO:0100316/112

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.000013 (0 hom.)
• Consequence: KCNQ1 NM_000218.3 synonymous
• Clinical Significance: Likely benign reviewed by expert panel B:4
• Conservation: PhyloP100: 0.371
• Publications: 0 publications found

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 Gene-Disease associations (from GenCC):

• long QT syndrome

  Inheritance: AD Classification: DEFINITIVE Submitted by: ClinGen
• long QT syndrome 1

  Inheritance: AD, AR Classification: DEFINITIVE, STRONG Submitted by: Labcorp Genetics (formerly Invitae), G2P
• Jervell and Lange-Nielsen syndrome

  Inheritance: AR Classification: DEFINITIVE Submitted by: ClinGen
• Jervell and Lange-Nielsen syndrome 1

  Inheritance: AR Classification: DEFINITIVE, STRONG Submitted by: PanelApp Australia, Labcorp Genetics (formerly Invitae), G2P
• atrial fibrillation, familial, 3

  Inheritance: AD Classification: STRONG Submitted by: Labcorp Genetics (formerly Invitae)
• short QT syndrome

  Inheritance: AD Classification: STRONG, SUPPORTIVE Submitted by: ClinGen, Orphanet
• short QT syndrome type 2

  Inheritance: AD Classification: STRONG Submitted by: Labcorp Genetics (formerly Invitae), G2P
• familial atrial fibrillation

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• Jervell and Lange-Nielsen syndrome

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
• hypertrophic cardiomyopathy

  Inheritance: AD Classification: NO_KNOWN Submitted by: ClinGen

ACMG classification

Our verdict: Likely_benign. The variant received -2 ACMG points.

• BP4: For more information check the summary or visit ClinGen Evidence Repository.
• BP7: For more information check the summary or visit ClinGen Evidence Repository.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
KCNQ1	NM_000218.3	c.840G>T	p.Val280Val	synonymous_variant	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.840G>T	p.Val280Val	synonymous_variant	Exon 6 of 16	1	NM_000218.3	ENSP00000155840.2

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 0.0000130 AC: 19 AN: 1461484 Hom.: 0 Cov.: 32 AF XY: 0.0000138 AC XY: 10 AN XY: 727056

African (AFR) AF: 0.00 AC: 0 AN: 33480

American (AMR) AF: 0.00 AC: 0 AN: 44714

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26134

East Asian (EAS) AF: 0.00 AC: 0 AN: 39700

South Asian (SAS) AF: 0.00 AC: 0 AN: 86254

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53052

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5768

European-Non Finnish (NFE) AF: 0.0000171 AC: 19 AN: 1111996

Other (OTH) AF: 0.00 AC: 0 AN: 60386

GnomAD4 genome Cov.: 33

Alfa AF: 0.0000413 Hom.: 0

Bravo AF: 0.00000378

ClinVar

Significance: Likely benign

Submissions summary: Benign:4

Revision: reviewed by expert panel

Submissions by phenotype

Long QT syndrome 1 Benign:1

Jul 01, 2025

ClinGen Potassium Channel Arrhythmia Variant Curation Expert Panel, ClinGen

Significance: Likely benign

Review Status: reviewed by expert panel

Collection Method: curation

NM_000218.3(KCNQ1):c.840G>T (p.Val280=) is a synonymous variant in exon 6. This variant is present in gnomAD v.4.1.0 at a maximum allele frequency of 0.00001610, with 19 alleles out of 1,180,028 total alleles in the European (non-Finnish) population, which is higher than the ClinGen Potassium Channel Arrhythmia VCEP PM2_Supporting threshold of <0.00001, but lower than the BS1 threshold of >0.0004, so neither criterion is met. The computational splicing predictor SpliceAI gives this silent variant a delta score of 0.06 for acceptor gain which is below the ClinGen Potassium Channel Arrhythmia VCEP BP7 threshold of <0.2 and does not strongly predict a splicing defect (BP4). In addition, the conservation tool PhyloP gives this variant a score of 0.275, which is below the Potassium Channel Arrhythmia VCEP BP7 threshold of <2.0 and indicates a low level of evolutionary conservation at this site (BP7). In summary, this variant meets the criteria to be classified as likely benign for long QT syndrome 1 based on the ACMG/AMP criteria applied, as specified by the ClinGen Potassium Channel Arrhythmia VCEP: BP4 and BP7. (VCEP specifications version 1.0.0; date of approval 03/04/2025). -

Long QT syndrome Benign:1

Jul 03, 2023

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Cardiovascular phenotype Benign:1

Feb 28, 2019

Ambry Genetics

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This alteration is classified as likely benign based on a combination of the following: seen in unaffected individuals, population frequency, intact protein function, lack of segregation with disease, co-occurrence, RNA analysis, in silico models, amino acid conservation, lack of disease association in case-control studies, and/or the mechanism of disease or impacted region is inconsistent with a known cause of pathogenicity. -

Cardiac arrhythmia Benign:1

Nov 06, 2022

Color Diagnostics, LLC DBA Color Health

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.53
CADD	Benign	7.7
DANN	Benign	0.54
PhyloP100		0.37
Mutation Taster		=100/0	polymorphism

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.060		Details are displayed if max score is > 0.2

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

Other links and lift over

dbSNP: rs1554893236; hg19: chr11-2594135;