20-63407198-T-G

Position:

chr20-63407198-T-G

Variant summary

Our verdict is Benign. Variant got -19 ACMG points: 1P and 20B. PP2BP4_StrongBP6_Very_StrongBS1BS2

The NM_172107.4(KCNQ2):c.2065A>C(p.Ile689Leu) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00109 in 1,606,336 control chromosomes in the GnomAD database, including 30 homozygotes. In-silico tool predicts a benign outcome for this variant. 15/20 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Benign (★★). Synonymous variant affecting the same amino acid position (i.e. I689I) has been classified as Likely benign.

Frequency

Genomes: 𝑓 0.00071 ( 1 hom., cov: 33)

Exomes 𝑓: 0.0011 ( 29 hom. )

Consequence

KCNQ2
NM_172107.4 missense

Scores

Clinical Significance

Benign criteria provided, multiple submitters, no conflicts B:4

Conservation

PhyloP100: 1.51

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 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Benign. Variant got -19 ACMG points.

PP2

Missense variant where missense usually causes diseases, KCNQ2

BP4

Computational evidence support a benign effect (MetaRNN=0.005797833).

BP6

Variant 20-63407198-T-G is Benign according to our data. Variant chr20-63407198-T-G is described in ClinVar as [Benign]. Clinvar id is 205848.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr20-63407198-T-G is described in Lovd as [Likely_benign].

BS1

Variant frequency is greater than expected in population sas. gnomad4 allele frequency = 0.000709 (108/152278) while in subpopulation SAS AF= 0.0137 (66/4822). AF 95% confidence interval is 0.011. There are 1 homozygotes in gnomad4. There are 80 alleles in male gnomad4 subpopulation. Median coverage is 33. This position pass quality control queck.

BS2

High AC in GnomAd4 at 108 AD gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
KCNQ2	NM_172107.4 linkuse as main transcript	c.2065A>C	p.Ile689Leu	missense_variant	17/17	ENST00000359125.7

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
KCNQ2	ENST00000359125.7 linkuse as main transcript	c.2065A>C	p.Ile689Leu	missense_variant	17/17	1	NM_172107.4	A1	O43526-1

Frequencies

GnomAD3 genomes

AF:

0.000710

AC:

108

AN:

152160

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0000241

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.000392

Gnomad ASJ

AF:

0.00115

Gnomad EAS

AF:

0.000193

Gnomad SAS

AF:

0.0137

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00316

Gnomad NFE

AF:

0.000382

Gnomad OTH

AF:

0.00143

GnomAD3 exomes

AF:

0.00213

AC:

507

AN:

238146

Hom.:

AF XY:

0.00291

AC XY:

382

AN XY:

131162

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.000555

Gnomad ASJ exome

AF:

0.000913

Gnomad EAS exome

AF:

0.00

Gnomad SAS exome

AF:

0.0138

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.000507

Gnomad OTH exome

AF:

0.000678

GnomAD4 exome

AF:

0.00113

AC:

1644

AN:

1454058

Hom.:

Cov.:

AF XY:

0.00162

AC XY:

1172

AN XY:

723644

show subpopulations

Gnomad4 AFR exome

AF:

0.0000897

Gnomad4 AMR exome

AF:

0.000627

Gnomad4 ASJ exome

AF:

0.000958

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.0144

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.000220

Gnomad4 OTH exome

AF:

0.00119

GnomAD4 genome

AF:

0.000709

AC:

108

AN:

152278

Hom.:

Cov.:

AF XY:

0.00107

AC XY:

AN XY:

74470

show subpopulations

Gnomad4 AFR

AF:

0.0000241

Gnomad4 AMR

AF:

0.000392

Gnomad4 ASJ

AF:

0.00115

Gnomad4 EAS

AF:

0.000193

Gnomad4 SAS

AF:

0.0137

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.000382

Gnomad4 OTH

AF:

0.00142

Alfa

AF:

0.000700

Hom.:

Bravo

AF:

0.000351

ExAC

AF:

0.00194

AC:

235

Asia WGS

AF:

0.00231

AC:

AN:

3478

ClinVar

Significance: Benign

Submissions summary: Benign:4

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

not specified

Benign:1

Benign, criteria provided, single submitter

clinical testing

GeneDx

Jul 05, 2016

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. -

Inborn genetic diseases

Benign:1

Benign, criteria provided, single submitter

clinical testing

Ambry Genetics

Apr 15, 2019

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. -

Early infantile epileptic encephalopathy with suppression bursts

Benign:1

Benign, criteria provided, single submitter

clinical testing

Invitae

Jan 30, 2024

- -

not provided

Benign:1

Benign, criteria provided, single submitter

clinical testing

CeGaT Center for Human Genetics Tuebingen

Apr 01, 2024

KCNQ2: BS1, BS2 -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.10

BayesDel_addAF

Benign

-0.35

BayesDel_noAF

Benign

-0.26

CADD

Benign

DANN

Benign

0.94

Eigen

Benign

-0.60

Eigen_PC

Benign

-0.51

FATHMM_MKL

Benign

0.69

LIST_S2

Benign

0.80

T;T;T;T;T;T;T;T;T

MetaRNN

Benign

0.0058

T;T;T;T;T;T;T;T;T

MetaSVM

Uncertain

0.53

MutationTaster

Benign

0.56

N;N;N;N;N;N;N;N;N

PrimateAI

Benign

0.45

Sift4G

Benign

0.50

T;T;T;T;.;T;T;T;T

Polyphen

0.0010

B;.;.;.;.;B;.;B;B

Vest4

0.12

MVP

0.31

MPC

0.62

ClinPred

0.0063

GERP RS

0.028

Varity_R

0.064

gMVP

0.20

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