8-132129996-C-T

Variant names:

Variant summary

Our verdict is Uncertain significance. The variant received 0 ACMG points: 1P and 1B. PP3BP6

The NM_004519.4(KCNQ3):c.1885G>A(p.Val629Ile) variant causes a missense, splice region change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000167 in 1,612,984 control chromosomes in the GnomAD database, with no homozygous occurrence. 2/3 splice prediction tools predicting alterations to normal splicing. 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. V629L) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.000033 ( 0 hom., cov: 33)

Exomes 𝑓: 0.000015 ( 0 hom. )

Consequence

KCNQ3
NM_004519.4 missense, splice_region

Scores

Splicing: ADA: 0.9987

Clinical Significance

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

Conservation

PhyloP100: 7.37

Publications

4 publications found

Variant links:

Genes affected

KCNQ3 (HGNC:6297): (potassium voltage-gated channel subfamily Q member 3) This gene encodes a protein that functions in the regulation of neuronal excitability. The encoded protein forms an M-channel by associating with the products of the related KCNQ2 or KCNQ5 genes, which both encode integral membrane proteins. M-channel currents are inhibited by M1 muscarinic acetylcholine receptors and are activated by retigabine, a novel anti-convulsant drug. Defects in this gene are a cause of benign familial neonatal convulsions type 2 (BFNC2), also known as epilepsy, benign neonatal type 2 (EBN2). Alternative splicing of this gene results in multiple transcript variants. [provided by RefSeq, May 2014]

KCNQ3 Gene-Disease associations (from GenCC):

seizures, benign familial neonatal, 2
Inheritance: AD Classification: STRONG, MODERATE Submitted by: Ambry Genetics, Labcorp Genetics (formerly Invitae)
benign familial infantile epilepsy
Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
benign neonatal seizures
Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
genetic developmental and epileptic encephalopathy
Inheritance: AR Classification: LIMITED Submitted by: Ambry Genetics

KCNQ3 links:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Uncertain_significance. The variant received 0 ACMG points.

PP3

Splicing predictors support a deleterious effect. Scorers claiming Pathogenic: dbscSNV1_ADA, dbscSNV1_RF. No scorers claiming Uncertain. Scorers claiming Benign: max_spliceai.

BP6

Variant 8-132129996-C-T is Benign according to our data. Variant chr8-132129996-C-T is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 449145.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
KCNQ3	NM_004519.4 link	c.1885G>A	p.Val629Ile	missense_variant, splice_region_variant	Exon 15 of 15	ENST00000388996.10	NP_004510.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
KCNQ3	ENST00000388996.10 link	c.1885G>A	p.Val629Ile	missense_variant, splice_region_variant	Exon 15 of 15	1	NM_004519.4	ENSP00000373648.3

Frequencies

GnomAD3 genomes

AF:

0.0000329

AC:

AN:

152052

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0000242

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.000131

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:

0.0000294

Gnomad OTH

AF:

0.00

GnomAD2 exomes

AF:

0.0000518

AC:

AN:

251010

AF XY:

0.0000295

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.000289

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000176

Gnomad OTH exome

AF:

0.000163

GnomAD4 exome

AF:

0.0000151

AC:

AN:

1460932

Hom.:

Cov.:

AF XY:

0.0000124

AC XY:

AN XY:

726768

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

33466

American (AMR)

AF:

0.000291

AC:

AN:

44724

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26136

East Asian (EAS)

AF:

0.00

AC:

AN:

39700

South Asian (SAS)

AF:

0.00

AC:

AN:

86214

European-Finnish (FIN)

AF:

0.00

AC:

AN:

53176

Middle Eastern (MID)

AF:

0.000193

AC:

AN:

5180

European-Non Finnish (NFE)

AF:

0.00000719

AC:

AN:

1112008

Other (OTH)

AF:

0.00

AC:

AN:

60328

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.466

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Exome Het

Variant carriers

<30

30-35

35-40

40-45

45-50

50-55

55-60

60-65

65-70

70-75

75-80

>80

Age

GnomAD4 genome

AF:

0.0000329

AC:

AN:

152052

Hom.:

Cov.:

AF XY:

0.0000269

AC XY:

AN XY:

74270

show subpopulations

African (AFR)

AF:

0.0000242

AC:

AN:

41366

American (AMR)

AF:

0.000131

AC:

AN:

15270

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3472

East Asian (EAS)

AF:

0.00

AC:

AN:

5186

South Asian (SAS)

AF:

0.00

AC:

AN:

4836

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10584

Middle Eastern (MID)

AF:

0.00

AC:

AN:

316

European-Non Finnish (NFE)

AF:

0.0000294

AC:

AN:

68020

Other (OTH)

AF:

0.00

AC:

AN:

2090

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.515

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Genome Het

Variant carriers

<30

30-35

35-40

40-45

45-50

50-55

55-60

60-65

65-70

70-75

75-80

>80

Age

Alfa

AF:

0.00

Hom.:

Bravo

AF:

0.0000680

ExAC

AF:

0.0000165

AC:

EpiCase

AF:

0.0000545

EpiControl

AF:

0.0000593

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:1Benign:2

Revision: criteria provided, conflicting classifications

LINK: link

Submissions by phenotype

Benign neonatal seizures

Uncertain:1

Oct 14, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This sequence change replaces valine, which is neutral and non-polar, with isoleucine, which is neutral and non-polar, at codon 629 of the KCNQ3 protein (p.Val629Ile). This variant is present in population databases (rs185511111, gnomAD 0.03%). This missense change has been observed in individual(s) with clinical features of KCNQ3-related conditions (internal data). ClinVar contains an entry for this variant (Variation ID: 449145). An algorithm developed to predict the effect of missense changes on protein structure and function (PolyPhen-2) suggests that this variant is likely to be disruptive. In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. -

Inborn genetic diseases

Benign:1

Jun 30, 2021

Ambry Genetics

Significance:Likely benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This alteration is classified as likely benign based on a combination of the following: seen in unaffected individuals, population frequency, intact protein function, lack of segregation with disease, co-occurrence, RNA analysis, in silico models, amino acid conservation, lack of disease association in case-control studies, and/or the mechanism of disease or impacted region is inconsistent with a known cause of pathogenicity. -

not provided

Benign:1

Jun 22, 2021

GeneDx

Significance:Likely benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Uncertain

0.38

BayesDel_addAF

Uncertain

0.015

BayesDel_noAF

Uncertain

0.090

CADD

Pathogenic

(source)

DANN

Uncertain

1.0

DEOGEN2

Uncertain

0.72

D;.;.;.;.

Eigen

Pathogenic

0.70

Eigen_PC

Pathogenic

0.72

FATHMM_MKL

Pathogenic

0.99

LIST_S2

Uncertain

0.97

D;D;D;D;D

M_CAP

Uncertain

0.28

MetaRNN

Uncertain

0.72

D;D;D;D;D

MetaSVM

Pathogenic

1.1

MutationAssessor

Uncertain

2.8

M;.;.;.;.

PhyloP100

7.4

PrimateAI

Benign

0.33

PROVEAN

Benign

-0.91

N;.;N;N;.

REVEL

Pathogenic

0.74

Sift

Uncertain

0.0020

D;.;D;D;.

Sift4G

Uncertain

0.0070

D;D;D;D;.

Polyphen

0.98

D;.;.;D;.

Vest4

0.50

MutPred

0.65

Loss of disorder (P = 0.1022);.;.;.;.;

MVP

0.73

MPC

0.46

ClinPred

0.54

GERP RS

5.7

Varity_R

0.46

gMVP

0.51

Mutation Taster

=55/45

polymorphism

(source)

Splicing

Name

Calibrated prediction

Score

Prediction

dbscSNV1_ADA

Pathogenic

1.0

dbscSNV1_RF

Pathogenic

0.89

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

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Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

Age Distribution

Age Distribution

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over