chr20-63433862-G-A

Variant names:

Variant summary

Our verdict is Benign. The variant received -19 ACMG points: 0P and 19B. BP4_ModerateBP6_Very_StrongBP7BS1BS2

The NM_172107.4(KCNQ2):c.1065C>T(p.Asp355Asp) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000682 in 1,613,944 control chromosomes in the GnomAD database, including 5 homozygotes. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Benign (★★).

Frequency

Genomes: 𝑓 0.0010 ( 2 hom., cov: 33)

Exomes 𝑓: 0.00065 ( 3 hom. )

Consequence

KCNQ2
NM_172107.4 synonymous

Scores

Clinical Significance

Benign criteria provided, multiple submitters, no conflicts B:5

Conservation

PhyloP100: 1.57

Publications

1 publications found

Variant links:

Genes affected

KCNQ2 (HGNC:6296): (potassium voltage-gated channel subfamily Q member 2) The M channel is a slowly activating and deactivating potassium channel that plays a critical role in the regulation of neuronal excitability. The M channel is formed by the association of the protein encoded by this gene and a related protein encoded by the KCNQ3 gene, both integral membrane proteins. M channel currents are inhibited by M1 muscarinic acetylcholine receptors and activated by retigabine, a novel anti-convulsant drug. Defects in this gene are a cause of benign familial neonatal convulsions type 1 (BFNC), also known as epilepsy, benign neonatal type 1 (EBN1). At least five transcript variants encoding five different isoforms have been found for this gene. [provided by RefSeq, Jul 2008]

KCNQ2 Gene-Disease associations (from GenCC):

complex neurodevelopmental disorder
Inheritance: AD Classification: DEFINITIVE Submitted by: ClinGen
developmental and epileptic encephalopathy, 7
Inheritance: AD Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Orphanet, Labcorp Genetics (formerly Invitae), G2P
neonatal encephalopathy with non-epileptic myoclonus
Inheritance: AD Classification: DEFINITIVE Submitted by: ClinGen
neonatal-onset developmental and epileptic encephalopathy
Inheritance: AD Classification: DEFINITIVE Submitted by: ClinGen
seizures, benign familial neonatal, 1
Inheritance: AD Classification: DEFINITIVE Submitted by: G2P
seizures, benign familial neonatal, 2
Inheritance: AD Classification: STRONG Submitted by: Labcorp Genetics (formerly Invitae)
benign familial infantile epilepsy
Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
benign familial neonatal-infantile seizures
Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
benign neonatal seizures
Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
malignant migrating partial seizures of infancy
Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet

KCNQ2 links:

ENSG00000293847 (HGNC:):

ENSG00000293847 links:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Benign. The variant received -19 ACMG points.

BP4

Computational evidence support a benign effect (BayesDel_noAF=-0.41).

BP6

Variant 20-63433862-G-A is Benign according to our data. Variant chr20-63433862-G-A is described in ClinVar as Benign. ClinVar VariationId is 205833.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

BP7

Synonymous conserved (PhyloP=1.57 with no splicing effect.

BS1

Variant frequency is greater than expected in population eas. GnomAd4 allele frequency = 0.00101 (154/152380) while in subpopulation EAS AF = 0.00116 (6/5190). AF 95% confidence interval is 0.000503. There are 2 homozygotes in GnomAd4. There are 106 alleles in the male GnomAd4 subpopulation. Median coverage is 33. This position passed quality control check.

BS2

High AC in GnomAd4 at 154 AD gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
KCNQ2	NM_172107.4 link	c.1065C>T	p.Asp355Asp	synonymous_variant	Exon 8 of 17	ENST00000359125.7	NP_742105.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
KCNQ2	ENST00000359125.7 link	c.1065C>T	p.Asp355Asp	synonymous_variant	Exon 8 of 17	1	NM_172107.4	ENSP00000352035.2

Frequencies

GnomAD3 genomes

AF:

0.00101

AC:

154

AN:

152262

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:

0.00115

Gnomad SAS

AF:

0.000207

Gnomad FIN

AF:

0.0111

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.000397

Gnomad OTH

AF:

0.000956

GnomAD2 exomes

AF:

0.00155

AC:

390

AN:

251282

AF XY:

0.00140

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.000381

Gnomad FIN exome

AF:

0.0136

Gnomad NFE exome

AF:

0.000660

Gnomad OTH exome

AF:

0.00196

GnomAD4 exome

AF:

0.000647

AC:

946

AN:

1461564

Hom.:

Cov.:

AF XY:

0.000611

AC XY:

444

AN XY:

727060

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

33478

American (AMR)

AF:

0.00

AC:

AN:

44710

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26136

East Asian (EAS)

AF:

0.000151

AC:

AN:

39688

South Asian (SAS)

AF:

0.0000464

AC:

AN:

86240

European-Finnish (FIN)

AF:

0.0127

AC:

677

AN:

53340

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5686

European-Non Finnish (NFE)

AF:

0.000187

AC:

208

AN:

1111906

Other (OTH)

AF:

0.000845

AC:

AN:

60380

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.486

Heterozygous variant carriers

119

178

238

297

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:

0.00101

AC:

154

AN:

152380

Hom.:

Cov.:

AF XY:

0.00142

AC XY:

106

AN XY:

74516

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

41588

American (AMR)

AF:

0.00

AC:

AN:

15314

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3472

East Asian (EAS)

AF:

0.00116

AC:

AN:

5190

South Asian (SAS)

AF:

0.000207

AC:

AN:

4834

European-Finnish (FIN)

AF:

0.0111

AC:

118

AN:

10626

Middle Eastern (MID)

AF:

0.00

AC:

AN:

294

European-Non Finnish (NFE)

AF:

0.000397

AC:

AN:

68036

Other (OTH)

AF:

0.000946

AC:

AN:

2114

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.489

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:

0.000457

Hom.:

Bravo

AF:

0.000136

Asia WGS

AF:

0.000577

AC:

AN:

3478

EpiCase

AF:

0.00

EpiControl

AF:

0.0000593

ClinVar

Significance: Benign

Submissions summary: Benign:5

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

not specified

Benign:1

Jun 20, 2014

GeneDx

Significance:Benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This variant is considered likely benign or benign based on one or more of the following criteria: it is a conservative change, it occurs at a poorly conserved position in the protein, it is predicted to be benign by multiple in silico algorithms, and/or has population frequency not consistent with disease.

KCNQ2-related disorder

Benign:1

Aug 20, 2019

PreventionGenetics, part of Exact Sciences

Significance:Benign

Review Status:no assertion criteria provided

Collection Method:clinical testing

This variant is classified as benign based on ACMG/AMP sequence variant interpretation guidelines (Richards et al. 2015 PMID: 25741868, with internal and published modifications).

Inborn genetic diseases

Benign:1

Dec 15, 2017

Ambry Genetics

Significance:Benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This alteration is classified as 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.

Developmental and epileptic encephalopathy

Benign:1

Dec 16, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

not provided

Benign:1

Nov 01, 2022

CeGaT Center for Human Genetics Tuebingen

Significance:Benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

KCNQ2: BP4, BP7, BS1, BS2

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

BayesDel_noAF

Benign

-0.41

CADD

Benign

(source)

DANN

Benign

0.85

PhyloP100

1.6

Mutation Taster

=99/1

polymorphism

(source)

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

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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