11-2585275-C-T

Variant names:

• chr11-2585275-C-T
• rs199473411
• NM_000218.3:c.1096C>T

Variant summary

Our verdict is Likely pathogenic. The variant received 6 ACMG points: 6P and 0B. PM2_Supporting PS4 PP3

This summary comes from the ClinGen Evidence Repository: NM_000218.3(KCNQ1):c.1096C>T is a missense variant that causes substitution of arginine with tryptophan at position 366. This variant is present in gnomAD v.4.0.0 at a maximum allele frequency of 0.0000008993, with 1 allele / 1111974 total alleles in the European non-Finnish population, which is lower than the ClinGen Potassium Channel Arrhythmia VCEP PM2_Supporting threshold of <0.00001 (PM2_Supporting). This variant is rare and has been reported in 7 apparently unrelated probands affected with long QT syndrome 1 (PS4; PMID:29497013, PMID:24606995, PMID:9693036, PMID:26063740, PMID:24363352, PMID:19841300). The computational predictor REVEL gives a score of 0.921, which is above the ClinGen Potassium Channel Arrhythmia VCEP PP3 threshold of >0.75 and predicts a damaging effect on KCNQ1 function (PP3). The variant has been reported to segregate with long QT syndrome 1 through the proband and 3 affected family members from one family, however, each affected family member lacks the confirmation of the Schwartz score >3.5 or QTc >480ms or syncope necessary to be included / counted for the PP1 code (PMID:21499742). This variant has been reported in at least one affected proband exhibiting QTc prolongation above 480 milliseconds, however, available reported details are not sufficiently specific for long QT syndrome 1, so the PP4 code is not met (PMID:29497013). This variant has been shown to disrupt KCNQ1 function in one experimental assay, manual patch clamp (PMID:16556865), and shown not to disrupt KCNQ1 function in another experimental assay, the Meiler Lab functional impact predictor (http://servers.meilerlab.org/servers/show?s_id=29), which has generated a prediction of normal effects of the mutant on IKs_classification, V1/2_classification, act_classification, and deact_classification (PMID:29021305), so neither PS3_Supporting nor BS3_Supporting were met. In summary, this variant meets the criteria to be classified as likely pathogenic for long QT syndrome 1 based on the ACMG/AMP criteria applied, as specified by the ClinGen Potassium Channel Arrhythmia VCEP: PS4, PM2_Supporting, and PP3. (VCEP specifications version 1.0.0; date of approval 03/04/2025). LINK:https://erepo.genome.network/evrepo/ui/classification/CA005255/MONDO:0100316/112

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: KCNQ1 NM_000218.3 missense
• Clinical Significance: Likely pathogenic reviewed by expert panel P:16 O:1
• Conservation: PhyloP100: 0.635
• Publications: 22 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: G2P, Labcorp Genetics (formerly Invitae)
• 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_pathogenic. The variant received 6 ACMG points.

• PS4: For more information check the summary or visit ClinGen Evidence Repository.
• PM2: For more information check the summary or visit ClinGen Evidence Repository.
• PP3: For more information check the summary or visit ClinGen Evidence Repository.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_000218.3. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	KCNQ1	NM_000218.3	MANE Select	c.1096C>T	p.Arg366Trp	missense	Exon 8 of 16	NP_000209.2
	KCNQ1	NM_001406837.1		c.826C>T	p.Arg276Trp	missense	Exon 9 of 17	NP_001393766.1
	KCNQ1	NM_181798.2		c.715C>T	p.Arg239Trp	missense	Exon 8 of 16	NP_861463.1	P51787-2

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	KCNQ1	ENST00000155840.12	TSL:1 MANE Select	c.1096C>T	p.Arg366Trp	missense	Exon 8 of 16	ENSP00000155840.2	P51787-1
	KCNQ1	ENST00000335475.6	TSL:1	c.715C>T	p.Arg239Trp	missense	Exon 8 of 16	ENSP00000334497.5	P51787-2
	KCNQ1	ENST00000910997.1		c.1093C>T	p.Arg365Trp	missense	Exon 8 of 16	ENSP00000581056.1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461648 Hom.: 0 Cov.: 31 AF XY: 0.00 AC XY: 0 AN XY: 727142

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

American (AMR) AF: 0.00 AC: 0 AN: 44722

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: 86258

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53226

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

European-Non Finnish (NFE) AF: 8.99e-7 AC: 1 AN: 1111974

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

GnomAD4 genome Cov.: 33

Alfa AF: 0.0000324 Hom.: 0

ClinVar

ClinVar submissions

Significance: Likely pathogenic

Revision: reviewed by expert panel

Pathogenic	VUS	Benign	Condition
7	-	-	Long QT syndrome 1 (7)
3	-	-	Long QT syndrome (3)
3	-	-	not provided (3)
1	-	-	Cardiovascular phenotype (1)
1	-	-	Congenital long QT syndrome (2)
1	-	-	Jervell and Lange-Nielsen syndrome 1 (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	1.0
CardioboostArm	Pathogenic	1.0
BayesDel_addAF	Pathogenic	0.50	D
BayesDel_noAF	Pathogenic	0.49
CADD	Pathogenic	27
DANN	Pathogenic	1.0
DEOGEN2	Pathogenic	0.93	D
Eigen	Uncertain	0.31
Eigen_PC	Benign	0.17
FATHMM_MKL	Benign	0.60	D
LIST_S2	Pathogenic	0.98	D
M_CAP	Pathogenic	0.93	D
MetaRNN	Pathogenic	0.98	D
MetaSVM	Pathogenic	1.1	D
MutationAssessor	Uncertain	2.8	M
PhyloP100		0.64
PrimateAI	Pathogenic	0.91	D
PROVEAN	Pathogenic	-7.3	D
REVEL	Pathogenic	0.92
Sift	Pathogenic	0.0	D
Sift4G	Pathogenic	0.0010	D
Polyphen		1.0	D
Vest4		0.93
MutPred		0.84		Loss of disorder (P = 0.0061)
MVP		0.97
MPC		1.2
ClinPred		0.99	D
GERP RS		0.65
Varity_R		0.90
gMVP		0.92
Mutation Taster		=2/98	disease causing (ClinVar)

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.070		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: rs199473411; hg19: chr11-2606505;