20-63407176-G-A

Variant names:

Variant summary

Our verdict is Benign. Variant got -12 ACMG points: 1P and 13B. PP2BP4_StrongBP6BS1BS2

The NM_172107.4(KCNQ2):c.2087C>T(p.Thr696Met) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000474 in 1,604,172 control chromosomes in the GnomAD database, including 1 homozygotes. In-silico tool predicts a benign outcome for this variant. 15/21 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

Frequency

Genomes: 𝑓 0.000053 ( 0 hom., cov: 33)

Exomes 𝑓: 0.000047 ( 1 hom. )

Consequence

KCNQ2
NM_172107.4 missense

Scores

Clinical Significance

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

Conservation

PhyloP100: 0.0140

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 -12 ACMG points.

PP2

Missense variant in the KCNQ2 gene, where missense mutations are typically associated with disease (based on misZ statistic). The gene has 319 curated pathogenic missense variants (we use a threshold of 10). The gene has 78 curated benign missense variants. Gene score misZ: 4.0411 (above the threshold of 3.09). Trascript score misZ: 3.6968 (above the threshold of 3.09). GenCC associations: The gene is linked to seizures, benign familial neonatal, 1, neonatal-onset developmental and epileptic encephalopathy, benign familial neonatal-infantile seizures, benign neonatal seizures, malignant migrating partial seizures of infancy, neonatal encephalopathy with non-epileptic myoclonus, complex neurodevelopmental disorder, seizures, benign familial neonatal, 2, developmental and epileptic encephalopathy, 7, benign familial infantile epilepsy.

BP4

Computational evidence support a benign effect (MetaRNN=0.023257107).

BP6

Variant 20-63407176-G-A is Benign according to our data. Variant chr20-63407176-G-A is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 461412.We mark this variant Likely_benign, oryginal submissions are: {Uncertain_significance=1, Benign=2}.

BS1

Variant frequency is greater than expected in population amr. gnomad4 allele frequency = 0.0000525 (8/152334) while in subpopulation AMR AF= 0.000261 (4/15312). AF 95% confidence interval is 0.0000887. There are 0 homozygotes in gnomad4. There are 5 alleles in male gnomad4 subpopulation. Median coverage is 33. This position pass quality control queck.

BS2

High AC in GnomAd4 at 8 AD gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
KCNQ2	NM_172107.4 link	c.2087C>T	p.Thr696Met	missense_variant	Exon 17 of 17	ENST00000359125.7	NP_742105.1	O43526-1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
KCNQ2	ENST00000359125.7 link	c.2087C>T	p.Thr696Met	missense_variant	Exon 17 of 17	1	NM_172107.4	ENSP00000352035.2		O43526-1

Frequencies

GnomAD3 genomes

AF:

0.0000526

AC:

AN:

152216

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0000482

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.000262

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

GnomAD3 exomes

AF:

0.000246

AC:

AN:

231844

Hom.:

AF XY:

0.000164

AC XY:

AN XY:

128124

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.00157

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad SAS exome

AF:

0.0000671

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000191

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000468

AC:

AN:

1451838

Hom.:

Cov.:

AF XY:

0.0000374

AC XY:

AN XY:

722304

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.00122

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.0000350

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.00000811

Gnomad4 OTH exome

AF:

0.0000166

GnomAD4 genome

AF:

0.0000525

AC:

AN:

152334

Hom.:

Cov.:

AF XY:

0.0000671

AC XY:

AN XY:

74490

show subpopulations

Gnomad4 AFR

AF:

0.0000481

Gnomad4 AMR

AF:

0.000261

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.0000294

Gnomad4 OTH

AF:

0.00

Alfa

AF:

0.0000292

Hom.:

Bravo

AF:

0.0000340

ExAC

AF:

0.000116

AC:

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:1Benign:2

Revision: criteria provided, conflicting classifications

LINK: link

Submissions by phenotype

not provided

Uncertain:1Benign:1

Uncertain significance, criteria provided, single submitter	clinical testing	Eurofins Ntd Llc (ga)	Feb 06, 2017	- -
Benign, criteria provided, single submitter	clinical testing	GeneDx	Jun 04, 2021	- -

Early infantile epileptic encephalopathy with suppression bursts

Benign:1

Benign, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Feb 03, 2025

- -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.068

BayesDel_addAF

Benign

-0.37

BayesDel_noAF

Benign

-0.32

CADD

Benign

4.0

DANN

Benign

0.96

DEOGEN2

Benign

0.29

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

Eigen

Benign

-1.2

Eigen_PC

Benign

-1.2

FATHMM_MKL

Benign

0.036

LIST_S2

Uncertain

0.91

D;D;D;D;D;D;D;D;D

M_CAP

Pathogenic

0.44

MetaRNN

Benign

0.023

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

MetaSVM

Uncertain

0.65

MutationAssessor

Benign

-0.11

.;.;.;.;.;N;.;.;.

PrimateAI

Benign

0.35

PROVEAN

Benign

-1.0

.;.;.;N;.;N;.;N;.

REVEL

Benign

0.29

Sift

Benign

0.18

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

Sift4G

Benign

0.17

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

Polyphen

0.0040

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

Vest4

0.052

MutPred

0.15

.;.;.;.;.;Loss of glycosylation at S695 (P = 0.0661);.;.;.;

MVP

0.56

MPC

0.65

ClinPred

0.031

GERP RS

-4.8

Varity_R

0.021

gMVP

0.26

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