11-2572979-G-C

Variant names:

Variant summary

Our verdict is Pathogenic. Variant got 18 ACMG points: 18P and 0B. PM1PM2PM5PP3_StrongPP5_Very_Strong

The NM_000218.3(KCNQ1):c.914G>C(p.Trp305Ser) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000000685 in 1,460,482 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Pathogenic (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. W305L) has been classified as Pathogenic.

Frequency

Genomes: not found (cov: 33)

Exomes 𝑓: 6.8e-7 ( 0 hom. )

Consequence

KCNQ1
NM_000218.3 missense

Scores

Clinical Significance

Pathogenic criteria provided, multiple submitters, no conflicts P:4O:1

Conservation

PhyloP100: 9.36

Variant links:

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 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Pathogenic. Variant got 18 ACMG points.

PM1

In a helix (size 11) in uniprot entity KCNQ1_HUMAN there are 25 pathogenic changes around while only 0 benign (100%) 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 chr11-2572979-G-T is described in Lovd as [Pathogenic].

PP3

MetaRNN computational evidence supports a deleterious effect, 0.995

PP5

Variant 11-2572979-G-C is Pathogenic according to our data. Variant chr11-2572979-G-C is described in ClinVar as [Pathogenic]. Clinvar id is 3127.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr11-2572979-G-C is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
KCNQ1	NM_000218.3 link	c.914G>C	p.Trp305Ser	missense_variant	Exon 6 of 16	ENST00000155840.12	NP_000209.2	P51787-1Q96AI9

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	UniProt
KCNQ1	ENST00000155840.12 link	c.914G>C	p.Trp305Ser	missense_variant	Exon 6 of 16	1	NM_000218.3	ENSP00000155840.2	P51787-1
KCNQ1	ENST00000335475.6 link	c.533G>C	p.Trp178Ser	missense_variant	Exon 6 of 16	1		ENSP00000334497.5	P51787-2
KCNQ1	ENST00000496887.7 link	c.653G>C	p.Trp218Ser	missense_variant	Exon 7 of 16	5		ENSP00000434560.2	E9PPZ0
KCNQ1	ENST00000646564.2 link	c.478-10456G>C		intron_variant	Intron 2 of 10			ENSP00000495806.2	A0A2R8YEQ9

Frequencies

GnomAD3 genomes

Cov.:

GnomAD3 exomes

AF:

0.00000401

AC:

AN:

249180

Hom.:

AF XY:

0.00000740

AC XY:

AN XY:

135116

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad SAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00000889

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

6.85e-7

AC:

AN:

1460482

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

726452

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.00

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.00

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

9.00e-7

Gnomad4 OTH exome

AF:

0.00

GnomAD4 genome

Cov.:

ExAC

AF:

0.00000824

AC:

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:4Other:1

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Jervell and Lange-Nielsen syndrome 1

Pathogenic:1

Mar 01, 1998

OMIM

Significance: Pathogenic

Review Status: no assertion criteria provided

Collection Method: literature only

- -

not provided

Pathogenic:1

Dec 13, 2023

GeneDx

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Identified in patients with LQTS and JLNS referred for genetic testing at GeneDx and in published literature (PMID: 9020846, 9781056, 15840476, 19490272, 19716085, 22456477, 23158531); Observed in homozygous state in a patient in published literature with JLNS and not observed in homozygous state in controls (PMID: 9781056, 9020846); Published functional studies demonstrate a damaging effect as the W305S variant results in decreased potassium channel current (PMID: 9312006); Not observed at a significant frequency in large population cohorts (gnomAD); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; This variant is associated with the following publications: (PMID: 19716085, 26344792, 9781056, 34505893, 10973849, 17999538, 15840476, 19490272, 23158531, 21451124, 22456477, 26669661, 32383558, 34076677, 9020846, 9312006) -

Long QT syndrome

Pathogenic:1

Apr 30, 2022

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

For these reasons, this variant has been classified as Pathogenic. This variant disrupts the p.Trp305 amino acid residue in KCNQ1. Other variant(s) that disrupt this residue have been observed in individuals with KCNQ1-related conditions (PMID: 22949429, 26344792), which suggests that this may be a clinically significant amino acid residue. Experimental studies have shown that this missense change affects KCNQ1 function (PMID: 9312006, 10090886, 21451124, 26344792). Algorithms developed to predict the effect of missense changes on protein structure and function (SIFT, PolyPhen-2, Align-GVGD) all suggest that this variant is likely to be disruptive. ClinVar contains an entry for this variant (Variation ID: 3127). This missense change has been observed in individuals with clinical features of long QT syndrome and Jervell and Lange-Nielsen syndrome (PMID: 9781056, 15840476, 19490272, 19716085, 21451124, 22456477, 23139254). It has also been observed to segregate with disease in related individuals. This variant is present in population databases (rs120074186, gnomAD 0.0009%). This sequence change replaces tryptophan, which is neutral and slightly polar, with serine, which is neutral and polar, at codon 305 of the KCNQ1 protein (p.Trp305Ser). -

Cardiovascular phenotype

Pathogenic:1

Mar 31, 2022

Ambry Genetics

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The p.W305S variant (also known as c.914G>C), located in coding exon 6 of the KCNQ1 gene, results from a G to C substitution at nucleotide position 914. The tryptophan at codon 305 is replaced by serine, an amino acid with highly dissimilar properties, and is located in the pore region of the protein. This variant has been reported in individuals and families with long QT syndrome (LQTS), as well as in LQTS clinical genetic testing cohorts; however, individual clinical details were limited (Tester DJ et al. Heart Rhythm, 2005;2:507-17; Jons C et al. Sci Transl Med, 2011 Mar;3:76ra28; Itoh H et al. Eur J Hum Genet, 2016 08;24:1160-6). This alteration was also detected in three homozygous cases, including two siblings and an unrelated proband, with autosomal recessive Jervell and Lange-Nielsen syndrome (Neyroud N et al. Eur. J. Hum. Genet. 1998;6:129-33). In vitro functional analyses suggest that this variant significantly reduces potassium current, although in one study the impact was lessened when the alteration was co-expressed with wildtype KCNQ1 (Chouabe C et al. EMBO J. 1997;16:5472-9; Jons C et al. Sci Transl Med. 2011;3:76ra28). Internal structural analysis indicates that this alteration is moderately disruptive in a sensitive region and more disruptive than a nearby known pathogenic variant (Ambry internal data). In addition, this alteration is predicted to be deleterious by in silico analysis. Based on the supporting evidence, this alteration is interpreted as a disease-causing mutation. -

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:9781056;PMID:15840476;PMID:19716085;PMID:9312006;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

0.99

BayesDel_addAF

Pathogenic

0.57

BayesDel_noAF

Pathogenic

0.59

CADD

Pathogenic

DANN

Uncertain

0.99

DEOGEN2

Pathogenic

0.99

D;.

Eigen

Pathogenic

0.83

Eigen_PC

Pathogenic

0.71

FATHMM_MKL

Pathogenic

0.99

LIST_S2

Pathogenic

0.99

D;D

M_CAP

Pathogenic

0.96

MetaRNN

Pathogenic

1.0

D;D

MetaSVM

Pathogenic

1.1

MutationAssessor

Pathogenic

4.2

H;.

PrimateAI

Uncertain

0.73

PROVEAN

Pathogenic

-14

D;D

REVEL

Pathogenic

0.95

Sift

Pathogenic

0.0

D;D

Sift4G

Pathogenic

0.0

D;D

Polyphen

1.0

D;D

Vest4

1.0

MutPred

0.95

Gain of glycosylation at W305 (P = 0.0053);.;

MVP

1.0

MPC

1.5

ClinPred

1.0

GERP RS

3.9

Varity_R

1.0

gMVP

1.0

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

Below is the list of publications found by LitVar. It may be empty.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over