rs12720449

Positions:

Variant summary

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

The NM_000218.3(KCNQ1):c.1343C>A(p.Pro448Gln) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000149 in 1,613,384 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 13/21 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. P448L) has been classified as Likely benign.

Frequency

Genomes: 𝑓 0.000013 ( 0 hom., cov: 33)

Exomes 𝑓: 0.000015 ( 0 hom. )

Consequence

KCNQ1
NM_000218.3 missense

Scores

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:3B:1

Conservation

PhyloP100: -0.179

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 chr11-2588804-C-T is described in Lovd as [Pathogenic].

BP4

Computational evidence support a benign effect (MetaRNN=0.09647837).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
KCNQ1	NM_000218.3 linkuse as main transcript	c.1343C>A	p.Pro448Gln	missense_variant	10/16	ENST00000155840.12

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
KCNQ1	ENST00000155840.12 linkuse as main transcript	c.1343C>A	p.Pro448Gln	missense_variant	10/16	1	NM_000218.3	P1	P51787-1
KCNQ1	ENST00000335475.6 linkuse as main transcript	c.962C>A	p.Pro321Gln	missense_variant	10/16	1			P51787-2
KCNQ1	ENST00000496887.7 linkuse as main transcript	c.986C>A	p.Pro329Gln	missense_variant	10/16	5
KCNQ1	ENST00000646564.2 linkuse as main transcript	c.803C>A	p.Pro268Gln	missense_variant	5/11

Frequencies

GnomAD3 genomes

AF:

0.0000132

AC:

AN:

152086

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0000241

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.00

Gnomad SAS

AF:

0.000207

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.00

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.0000719

AC:

AN:

250376

Hom.:

AF XY:

0.0000590

AC XY:

AN XY:

135480

show subpopulations

Gnomad AFR exome

AF:

0.0000619

Gnomad AMR exome

AF:

0.0000289

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad SAS exome

AF:

0.000491

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00000883

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000151

AC:

AN:

1461180

Hom.:

Cov.:

AF XY:

0.0000151

AC XY:

AN XY:

726868

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.0000224

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.000151

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.00000360

Gnomad4 OTH exome

AF:

0.0000663

GnomAD4 genome

AF:

0.0000131

AC:

AN:

152204

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

74414

show subpopulations

Gnomad4 AFR

AF:

0.0000241

Gnomad4 AMR

AF:

0.00

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.000208

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.00

Gnomad4 OTH

AF:

0.00

Bravo

AF:

0.00000756

ExAC

AF:

0.0000988

AC:

EpiCase

AF:

0.00

EpiControl

AF:

0.0000593

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:3Benign:1

Revision: criteria provided, conflicting classifications

LINK: link

Submissions by phenotype

Long QT syndrome

Uncertain:1Benign:1

Benign, criteria provided, single submitter	clinical testing	Invitae	Jan 04, 2024	- -
Uncertain significance, criteria provided, single submitter	clinical testing	All of Us Research Program, National Institutes of Health	Jun 26, 2023	This missense variant replaces proline with glutamine at codon 448 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 not been reported in individuals affected with KCNQ1-related disorders in the literature. This variant has been identified in 18/250376 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. -

Cardiovascular phenotype

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Jun 15, 2018

The p.P448Q variant (also known as c.1343C>A), located in coding exon 10 of the KCNQ1 gene, results from a C to A substitution at nucleotide position 1343. The proline at codon 448 is replaced by glutamine, an amino acid with similar properties. This amino acid position is poorly conserved in available vertebrate species. In addition, the in silico prediction for this alteration is inconclusive. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -

Cardiac arrhythmia

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Color Diagnostics, LLC DBA Color Health

Nov 16, 2022

This missense variant replaces proline with glutamine at codon 448 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 not been reported in individuals affected with KCNQ1-related disorders in the literature. This variant has been identified in 18/250376 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. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.077

BayesDel_addAF

Benign

-0.11

BayesDel_noAF

Uncertain

-0.060

CADD

Benign

1.3

DANN

Benign

0.89

DEOGEN2

Uncertain

0.54

D;.;.

Eigen

Benign

-0.83

Eigen_PC

Benign

-0.80

FATHMM_MKL

Benign

0.10

LIST_S2

Benign

0.47

T;T;T

M_CAP

Pathogenic

0.38

MetaRNN

Benign

0.096

T;T;T

MetaSVM

Uncertain

0.69

MutationAssessor

Benign

0.69

N;.;.

MutationTaster

Benign

1.0

N;N

PrimateAI

Benign

0.24

PROVEAN

Benign

-0.77

N;.;N

REVEL

Uncertain

0.51

Sift

Benign

0.12

T;.;T

Sift4G

Benign

0.61

T;.;T

Polyphen

0.0010

B;.;B

Vest4

0.25

MutPred

0.27

Loss of catalytic residue at P447 (P = 0.0102);.;.;

MVP

0.93

MPC

0.34

ClinPred

0.030

GERP RS

4.1

Varity_R

0.043

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