11-2662023-G-C

Variant names:

• chr11-2662023-G-C
• rs753256800
• NM_000218.3:c.1456G>C

Variant summary

Our verdict is Uncertain significance. The variant received 3 ACMG points: 3P and 0B. PM2 PP2

The NM_000218.3(KCNQ1):​c.1456G>C​(p.Ala486Pro) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. Variant has been reported in ClinVar as Uncertain significance (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. A486T) has been classified as Uncertain significance.

• Frequency: Genomes: not found (cov: 33)
• Consequence: KCNQ1 NM_000218.3 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 2.39
• Publications: 1 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]

KCNQ1OT1 (HGNC:6295): (KCNQ1 opposite strand/antisense transcript 1) Human chromosomal region 11p15.5 contains two clusters of epigenetically-regulated genes that are expressed from only one chromosome in a parent-of-origin manner. Each cluster, or imprinted domain, is regulated by a functionally independent imprinting control region (ICR). The human CDKN1C/KCNQ1OT1 domain is regulated by an ICR located in an intron of KCNQ1, and contains at least eight genes that are expressed exclusively or preferentially from the maternally-inherited allele. The DNA of the ICR is specifically methylated on the maternally-inherited chromosome, and unmethylated on the paternally-inherited chromosome. The ICR contains the promoter of the KCNQ1OT1 gene that is exclusively expressed from the paternal allele. The KCNQ1OT1 transcript is the antisense to the KCNQ1 gene and is a unspliced long non-coding RNA. It interacts with chromatin and regulates transcription of multiple target genes through epigenetic modifications. The transcript is abnormally expressed from both chromosomes in most patients with Beckwith-Wiedemann syndrome, and the transcript also plays an important role in colorectal carcinogenesis. [provided by RefSeq, Apr 2012]

KCNQ1OT1 Gene-Disease associations (from GenCC):

• Beckwith-Wiedemann syndrome

  Inheritance: Unknown Classification: LIMITED Submitted by: Labcorp Genetics (formerly Invitae)

ACMG classification

Our verdict: Uncertain_significance. The variant received 3 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• 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.

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.1456G>C	p.Ala486Pro	missense	Exon 11 of 16	NP_000209.2
	KCNQ1OT1	NR_002728.4	MANE Select	n.37972C>G		non_coding_transcript_exon	Exon 1 of 1
	KCNQ1	NM_001406836.1		c.1360G>C	p.Ala454Pro	missense	Exon 10 of 15	NP_001393765.1

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	KCNQ1	ENST00000155840.12	TSL:1 MANE Select	c.1456G>C	p.Ala486Pro	missense	Exon 11 of 16	ENSP00000155840.2
	KCNQ1	ENST00000335475.6	TSL:1	c.1075G>C	p.Ala359Pro	missense	Exon 11 of 16	ENSP00000334497.5
	KCNQ1OT1	ENST00000597346.1	TSL:6 MANE Select	n.37972C>G		non_coding_transcript_exon	Exon 1 of 1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 34

GnomAD4 genome Cov.: 33

ClinVar

ClinVar submissions as Germline

Significance: Uncertain significance

Revision: criteria provided, single submitter

Pathogenic	VUS	Benign	Condition
-	1	-	Long QT syndrome (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.31
CardioboostArm	Uncertain	0.25
BayesDel_addAF	Pathogenic	0.39	D
BayesDel_noAF	Pathogenic	0.32
CADD	Benign	22
DANN	Uncertain	0.98
DEOGEN2	Uncertain	0.54	D
Eigen	Benign	-0.53
Eigen_PC	Benign	-0.60
FATHMM_MKL	Benign	0.54	D
LIST_S2	Uncertain	0.90	D
M_CAP	Pathogenic	0.63	D
MetaRNN	Uncertain	0.51	D
MetaSVM	Pathogenic	1.1	D
MutationAssessor	Benign	1.7	L
PhyloP100		2.4
PrimateAI	Uncertain	0.53	T
PROVEAN	Benign	-1.9	N
REVEL	Pathogenic	0.69
Sift	Benign	0.045	D
Sift4G	Benign	0.15	T
Polyphen		0.98	D
Vest4		0.55
MutPred		0.67		Gain of disorder (P = 0.0197)
MVP		0.94
MPC		1.3
ClinPred		0.28	T
GERP RS		1.5
Varity_R		0.36
gMVP		0.48
Mutation Taster		=54/46	polymorphism

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: rs753256800; hg19: chr11-2683253;