11-2587576-T-G

Variant summary

Our verdict is Pathogenic. Variant got 10 ACMG points: 10P and 0B. PM1 PM2 PM5 PP3_Strong

The NM_000218.3(KCNQ1):c.1135T>G(p.Trp379Gly) variant causes a missense change. 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 Uncertain significance (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. W379R) has been classified as Likely pathogenic.

• Frequency: Genomes: not found (cov: 33)
• Consequence: KCNQ1 NM_000218.3 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1 O:1
• Conservation: PhyloP100: 6.96

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 10 ACMG points.

• PM1: In a hotspot region, there are 3 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 14 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 chr11-2587576-T-C is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 67013.We mark this variant Likely_pathogenic, oryginal submissions are: {Pathogenic=2, Uncertain_significance=1, not_provided=1}.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.988

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
KCNQ1	NM_000218.3	c.1135T>G	p.Trp379Gly	missense_variant	9/16	ENST00000155840.12

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
KCNQ1	ENST00000155840.12	c.1135T>G	p.Trp379Gly	missense_variant	9/16	1	NM_000218.3	P1
KCNQ1	ENST00000335475.6	c.754T>G	p.Trp252Gly	missense_variant	9/16	1
KCNQ1	ENST00000496887.7	c.778T>G	p.Trp260Gly	missense_variant	9/16	5
KCNQ1	ENST00000646564.2	c.595T>G	p.Trp199Gly	missense_variant	4/11

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 32

GnomAD4 genome Cov.: 33

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1 Other:1

Revision: criteria provided, single submitter

Submissions by phenotype

not provided Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

GeneDx

Jan 17, 2020

Identified in a patient referred for LQTS genetic testing in the published literature (Kapplinger et al., 2009); Not observed in large population cohorts (Lek et al., 2016); In silico analysis, which includes protein predictors and evolutionary conservation, supports a deleterious effect; Different missense changes at this residue (p.W379R, p.W379S) have been reported in the Human Gene Mutation Database in association with LQTS and sudden unexplained death (Stenson et al., 2014); however, the pathogenicity of these variants has not been definitively determined; This variant is associated with the following publications: (PMID: 19716085) -

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:19716085). 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
CardioboostArm	Pathogenic	1.0
BayesDel_addAF	Pathogenic	0.55	D
BayesDel_noAF	Pathogenic	0.56
Cadd	Pathogenic	28
Dann	Benign	0.97
DEOGEN2	Pathogenic	0.97	D;.;.
Eigen	Uncertain	0.60
Eigen_PC	Uncertain	0.48
FATHMM_MKL	Pathogenic	0.97	D
LIST_S2	Uncertain	0.97	D;T;D
M_CAP	Pathogenic	0.96	D
MetaRNN	Pathogenic	0.99	D;D;D
MetaSVM	Pathogenic	1.0	D
MutationAssessor	Pathogenic	2.9	M;.;.
MutationTaster	Benign	1.0	D;D
PrimateAI	Pathogenic	0.83	D
PROVEAN	Pathogenic	-13	D;.;D
REVEL	Pathogenic	0.90
Sift	Uncertain	0.0010	D;.;D
Sift4G	Pathogenic	0.0	D;.;D
Polyphen		1.0	D;.;D
Vest4		0.97
MutPred		0.85		Loss of stability (P = 0.0526);.;.;
MVP		0.98
MPC		1.5
ClinPred		1.0	D
GERP RS		4.7
Varity_R		0.92
gMVP		0.98

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.040		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: rs199472768; hg19: chr11-2608806;