11-2583478-C-A

Variant names:

• chr11-2583478-C-A
• rs199472755
• NM_000218.3:c.965C>A

Variant summary

Our verdict is Pathogenic. The variant received 12 ACMG points: 12P and 0B. PM1 PM2 PM5 PP2 PP3_Strong PP5

The NM_000218.3(KCNQ1):​c.965C>A​(p.Thr322Lys) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000137 in 1,461,704 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 13/23 in silico tools predict a damaging outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. T322R) has been classified as Likely pathogenic.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.0000014 (0 hom.)
• Consequence: KCNQ1 NM_000218.3 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:1 U:2 O:1
• Conservation: PhyloP100: 7.42
• Publications: 20 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: Pathogenic. The variant received 12 ACMG points.

• PM1: In a hotspot region, there are 23 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 19 uncertain in NM_000218.3
• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr11-2583478-C-G is described in ClinVar as Pathogenic/Likely_pathogenic. ClinVar VariationId is 200830.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
• PP2: Missense variant in the gene, where a lot of missense mutations are associated with disease in ClinVar. The gene has 212 curated pathogenic missense variants (we use a threshold of 10). The gene has 12 curated benign missense variants. Gene score misZ: 1.8321 (below the threshold of 3.09). Trascript score misZ: 0.90233 (below the threshold of 3.09). GenCC associations: The gene is linked to short QT syndrome type 2, long QT syndrome 1, Jervell and Lange-Nielsen syndrome 1, long QT syndrome, short QT syndrome, Jervell and Lange-Nielsen syndrome, hypertrophic cardiomyopathy, familial atrial fibrillation, atrial fibrillation, familial, 3.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.989
• PP5: Variant 11-2583478-C-A is Pathogenic according to our data. Variant chr11-2583478-C-A is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 53150.

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

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	KCNQ1	NM_000218.3	MANE Select	c.965C>A	p.Thr322Lys	missense	Exon 7 of 16	NP_000209.2
	KCNQ1	NM_001406836.1		c.965C>A	p.Thr322Lys	missense	Exon 7 of 15	NP_001393765.1
	KCNQ1	NM_001406837.1		c.695C>A	p.Thr232Lys	missense	Exon 8 of 17	NP_001393766.1

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	KCNQ1	ENST00000155840.12	TSL:1 MANE Select	c.965C>A	p.Thr322Lys	missense	Exon 7 of 16	ENSP00000155840.2
	KCNQ1	ENST00000335475.6	TSL:1	c.584C>A	p.Thr195Lys	missense	Exon 7 of 16	ENSP00000334497.5
	KCNQ1	ENST00000713725.1		c.824C>A	p.Thr275Lys	missense	Exon 6 of 15	ENSP00000519029.1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 0.00000137 AC: 2 AN: 1461704 Hom.: 0 Cov.: 31 AF XY: 0.00000138 AC XY: 1 AN XY: 727150

African (AFR) AF: 0.00 AC: 0 AN: 33474

American (AMR) AF: 0.00 AC: 0 AN: 44724

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26136

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: 53334

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

European-Non Finnish (NFE) AF: 0.00000180 AC: 2 AN: 1111920

Other (OTH) AF: 0.00 AC: 0 AN: 60394

GnomAD4 genome Cov.: 33

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:1 Uncertain:2 Other:1

Revision: criteria provided, conflicting classifications

Submissions by phenotype

Long QT syndrome 1 Pathogenic:1

May 27, 2019

MVZ Martinsried, Medicover Genetics

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Long QT syndrome Uncertain:1

Sep 23, 2024

All of Us Research Program, National Institutes of Health

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Cardiovascular phenotype Uncertain:1

Sep 25, 2015

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The c.965C>A (p.T322K) alteration is located in exon 7 (coding exon 7) of the KCNQ1 gene. This alteration results from a C to A substitution at nucleotide position 965, causing the threonine (T) at amino acid position 322 to be replaced by a lysine (K). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear.

Congenital long QT syndrome Other:1

Cardiovascular Biomedical Research Unit, Royal Brompton & Harefield NHS Foundation Trust

Significance: not provided

Review Status: no classification provided

Collection Method: literature only

This variant has been reported as associated with Long QT syndrome in the following publications (PMID:19862833). This is a literature report, and does not necessarily reflect the clinical interpretation of the Imperial College / Royal Brompton Cardiovascular Genetics laboratory.

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.97
CardioboostArm	Pathogenic	1.0
BayesDel_addAF	Pathogenic	0.58	D
BayesDel_noAF	Pathogenic	0.59
CADD	Pathogenic	32
DANN	Uncertain	0.99
DEOGEN2	Pathogenic	0.99	D
Eigen	Pathogenic	0.69
Eigen_PC	Uncertain	0.56
FATHMM_MKL	Benign	0.75	D
LIST_S2	Uncertain	0.93	D
M_CAP	Pathogenic	0.90	D
MetaRNN	Pathogenic	0.99	D
MetaSVM	Pathogenic	1.1	D
MutationAssessor	Pathogenic	4.1	H
PhyloP100		7.4
PrimateAI	Pathogenic	0.80	D
PROVEAN	Pathogenic	-5.4	D
REVEL	Pathogenic	0.95
Sift	Pathogenic	0.0	D
Sift4G	Pathogenic	0.0010	D
Polyphen		1.0	D
Vest4		0.94
MutPred		0.95		Gain of methylation at T322 (P = 0.0071)
MVP		0.98
MPC		1.3
ClinPred		1.0	D
GERP RS		3.0
Varity_R		0.97
gMVP		1.0
Mutation Taster		=4/96	disease causing (ClinVar)

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

Other links and lift over

dbSNP: rs199472755; hg19: chr11-2604708;