11-2588799-C-G

Variant names:

Variant summary

Our verdict is Uncertain significance. Variant got 0 ACMG points: 2P and 2B. PM5BP4_Moderate

The NM_000218.3(KCNQ1):c.1338C>G(p.Asp446Glu) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000124 in 1,613,166 control chromosomes in the GnomAD database, including 1 homozygotes. In-silico tool predicts a benign outcome for this variant. 12/21 in silico tools predict a benign 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. D446N) has been classified as Pathogenic.

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 33)

Exomes 𝑓: 0.000013 ( 1 hom. )

Consequence

KCNQ1
NM_000218.3 missense

Scores

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:2B:1O:1

Conservation

PhyloP100: 0.0710

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 Uncertain_significance. Variant got 0 ACMG points.

PM5

Other missense variant is known to change same aminoacid residue: Variant chr11-2588797-G-A is described in Lovd as [Pathogenic].

BP4

Computational evidence support a benign effect (MetaRNN=0.07501894).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
KCNQ1	NM_000218.3 link	c.1338C>G	p.Asp446Glu	missense_variant	Exon 10 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.1338C>G	p.Asp446Glu	missense_variant	Exon 10 of 16	1	NM_000218.3	ENSP00000155840.2	P51787-1
KCNQ1	ENST00000335475.6 link	c.957C>G	p.Asp319Glu	missense_variant	Exon 10 of 16	1		ENSP00000334497.5	P51787-2
KCNQ1	ENST00000496887.7 link	c.981C>G	p.Asp327Glu	missense_variant	Exon 10 of 16	5		ENSP00000434560.2	E9PPZ0
KCNQ1	ENST00000646564.2 link	c.798C>G	p.Asp266Glu	missense_variant	Exon 5 of 11			ENSP00000495806.2	A0A2R8YEQ9

Frequencies

GnomAD3 genomes

AF:

0.00000657

AC:

AN:

152144

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.00

Gnomad SAS

AF:

0.00

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.00

Gnomad OTH

AF:

0.000478

GnomAD3 exomes

AF:

0.0000719

AC:

AN:

250294

Hom.:

AF XY:

0.0000591

AC XY:

AN XY:

135446

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.000521

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:

0.00

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000130

AC:

AN:

1461022

Hom.:

Cov.:

AF XY:

0.00000963

AC XY:

AN XY:

726784

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.000425

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:

0.00

Gnomad4 OTH exome

AF:

0.00

GnomAD4 genome

AF:

0.00000657

AC:

AN:

152144

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

74318

show subpopulations

Gnomad4 AFR

AF:

0.00

Gnomad4 AMR

AF:

0.00

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.00

Gnomad4 OTH

AF:

0.000478

Bravo

AF:

0.0000227

ExAC

AF:

0.0000741

AC:

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:2Benign:1Other:1

Revision: criteria provided, conflicting classifications

LINK: link

Submissions by phenotype

Long QT syndrome

Uncertain:1Benign:1

Nov 29, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Aug 23, 2024

All of Us Research Program, National Institutes of Health

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This missense variant replaces aspartic acid with glutamic acid at codon 446 of the KCNQ1 protein. Computational prediction is inconclusive regarding the impact of this variant on protein structure and function (internally defined REVEL score threshold 0.5 < inconclusive < 0.7, PMID: 27666373). A functional study has shown that this variant causes abnormal channel function when expressed in a homozygous state in HEK293 cells, while the differences between the heterozygous and wild-type forms are not significant (PMID: 38256028). This variant has been reported in an individual affected with long QT syndrome (PMID: 25661095), in four other probands suspected of having the condition, and in several unaffected family members (PMID:19716085, 38256028). This variant has been identified in 18/250294 chromosomes in the general population by the Genome Aggregation Database (gnomAD). The available evidence is insufficient to determine the role of this variant in disease conclusively. Therefore, this variant is classified as a Variant of Uncertain Significance. -

Cardiac arrhythmia

Uncertain:1

Mar 01, 2023

Color Diagnostics, LLC DBA Color Health

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This missense variant replaces aspartic acid with glutamic acid at codon 446 of the KCNQ1 protein. Computational prediction is inconclusive regarding the impact of this variant on protein structure and function (internally defined REVEL score threshold 0.5 < inconclusive < 0.7, PMID: 27666373). To our knowledge, functional studies have not been reported for this variant. This variant has been reported in an individual affected with long QT syndrome (PMID: 25661095) and two individuals referred for long QT syndrome genetic test (PMID:19716085). This variant has been identified in 18/250294 chromosomes in the general population by the Genome Aggregation Database (gnomAD). The available evidence is insufficient to determine the role of this variant in disease conclusively. Therefore, this variant is classified as a Variant of Uncertain Significance. -

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: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

Benign

0.082

BayesDel_addAF

Uncertain

0.017

BayesDel_noAF

Uncertain

0.13

CADD

Benign

2.0

DANN

Benign

0.85

DEOGEN2

Benign

0.36

T;.;.

Eigen

Benign

-1.0

Eigen_PC

Benign

-1.1

FATHMM_MKL

Benign

0.078

LIST_S2

Benign

0.49

T;T;T

M_CAP

Uncertain

0.24

MetaRNN

Benign

0.075

T;T;T

MetaSVM

Uncertain

0.61

MutationAssessor

Benign

1.5

L;.;.

PrimateAI

Benign

0.36

PROVEAN

Benign

-0.82

N;.;N

REVEL

Uncertain

0.59

Sift

Benign

0.41

T;.;T

Sift4G

Benign

0.58

T;.;T

Polyphen

0.028

B;.;B

Vest4

0.74

MutPred

0.17

Gain of glycosylation at P448 (P = 0.0568);.;.;

MVP

0.91

MPC

0.35

ClinPred

0.031

GERP RS

-4.8

Varity_R

0.052

gMVP

0.32

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

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