chr11-2572089-G-T

Position:

• chr11-2572089-G-T

Variant summary

Our verdict is Pathogenic. Variant got 12 ACMG points: 12P and 0B. PM1 PM2 PM5 PP3_Strong PP5_Moderate

The ENST00000155840.12(KCNQ1):​c.760G>T​(p.Val254Leu) variant causes a missense change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Likely pathogenic (★). Another nucleotide change resulting in same amino acid change has been previously reported as Uncertain significancein ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. V254M) has been classified as Pathogenic.

• Frequency: Genomes: not found (cov: 33)
• Consequence: KCNQ1 ENST00000155840.12 missense
• Clinical Significance: Likely pathogenic criteria provided, single submitter P:1 O:1
• Conservation: PhyloP100: 7.58

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 12 ACMG points.

• PM1: In a hotspot region, there are 7 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 9 uncertain in ENST00000155840.12
• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr11-2572089-G-A is described in ClinVar as [Pathogenic]. Clinvar id is 3118.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.971
• PP5: Variant 11-2572089-G-T is Pathogenic according to our data. Variant chr11-2572089-G-T is described in ClinVar as [Likely_pathogenic]. Clinvar id is 53096.Status of the report is criteria_provided_single_submitter, 1 stars. Variant chr11-2572089-G-T is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
KCNQ1	NM_000218.3	c.760G>T	p.Val254Leu	missense_variant	5/16	ENST00000155840.12	NP_000209.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
KCNQ1	ENST00000155840.12	c.760G>T	p.Val254Leu	missense_variant	5/16	1	NM_000218.3	ENSP00000155840	P1
KCNQ1	ENST00000335475.6	c.379G>T	p.Val127Leu	missense_variant	5/16	1		ENSP00000334497
KCNQ1	ENST00000496887.7	c.499G>T	p.Val167Leu	missense_variant	6/16	5		ENSP00000434560
KCNQ1	ENST00000646564.2	c.478-11346G>T		intron_variant				ENSP00000495806

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 33

ClinVar

Significance: Likely pathogenic

Submissions summary: Pathogenic:1 Other:1

Revision: criteria provided, single submitter

Submissions by phenotype

Cardiovascular phenotype Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

Ambry Genetics

Jan 04, 2017

The p.V254L variant (also known as c.760G>T), located in coding exon 5 of the KCNQ1 gene, results from a G to T substitution at nucleotide position 760. The valine at codon 254 is replaced by leucine, an amino acid with highly similar properties, and is located in the S4-S5 linker region. This variant has been reported in individuals with long QT syndrome (LQTS) (Zareba W et al. J. Cardiovasc. Electrophysiol., 2003 Nov;14:1149-53; Napolitano C et al. JAMA, 2005 Dec;294:2975-80). Alternate amino acid substitutions at this position (p.V254M, p.V254A) have also been reported to adversely affect the voltage-gated potassium ion channel in individuals with LQTS (Wang Z et al. J Cardiovasc Electrophysiol. 1999;10(6):817-26; Labro AJ et al. J. Biol. Chem., 2011 Jan;286:717-25). This amino acid position is highly conserved in available vertebrate species. In addition, this alteration is predicted to be deleterious by in silico analysis. Based on the majority of available evidence to date, this variant is likely to be pathogenic. -

Congenital long QT syndrome Other:1

not provided, no classification provided

literature only

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

-

This variant has been reported as associated with Long QT syndrome in the following publications (PMID:14678125;PMID:16414944;PMID:17999538). 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 v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	1.0
BayesDel_addAF	Pathogenic	0.54	D
BayesDel_noAF	Pathogenic	0.53
CADD	Pathogenic	28
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.98	.;D;.
Eigen	Uncertain	0.62
Eigen_PC	Uncertain	0.54
FATHMM_MKL	Pathogenic	0.97	D
LIST_S2	Pathogenic	0.98	D;D;D
M_CAP	Pathogenic	0.68	D
MetaRNN	Pathogenic	0.97	D;D;D
MetaSVM	Pathogenic	1.1	D
MutationAssessor	Uncertain	2.2	.;M;.
MutationTaster	Benign	1.0	D;D
PrimateAI	Pathogenic	0.84	D
PROVEAN	Uncertain	-2.9	D;D;D
REVEL	Pathogenic	0.91
Sift	Uncertain	0.0010	D;D;D
Sift4G	Uncertain	0.0030	D;D;D
Polyphen		0.99, 1.0	.;D;D
Vest4		0.98, 0.95
MutPred		0.88		.;Loss of helix (P = 0.0167);.;
MVP		0.98
MPC		1.1
ClinPred		0.99	D
GERP RS		4.1
Varity_R		0.94
gMVP		0.97

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: rs120074179; hg19: chr11-2593319;