rs12481082

Variant names:

Variant summary

Our verdict is Likely benign. The variant received -4 ACMG points: 1P and 5B. PP2BP6BS2

The NM_172107.4(KCNQ2):c.2564C>T(p.Ser855Leu) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000622 in 1,606,940 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Synonymous variant affecting the same amino acid position (i.e. S855S) has been classified as Likely benign.

Frequency

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

Exomes 𝑓: 0.0000055 ( 0 hom. )

Consequence

KCNQ2
NM_172107.4 missense

Scores

Clinical Significance

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

Conservation

PhyloP100: 7.87

Publications

0 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:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Likely_benign. The variant received -4 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 benign familial infantile epilepsy, malignant migrating partial seizures of infancy, developmental and epileptic encephalopathy, 7, benign familial neonatal-infantile seizures, benign neonatal seizures, neonatal-onset developmental and epileptic encephalopathy, complex neurodevelopmental disorder, seizures, benign familial neonatal, 2, seizures, benign familial neonatal, 1, neonatal encephalopathy with non-epileptic myoclonus.

BP6

Variant 20-63406699-G-A is Benign according to our data. Variant chr20-63406699-G-A is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 21780.

BS2

High AC in GnomAdExome4 at 8 AD gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
KCNQ2	NM_172107.4 link	c.2564C>T	p.Ser855Leu	missense_variant	Exon 17 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.2564C>T	p.Ser855Leu	missense_variant	Exon 17 of 17	1	NM_172107.4	ENSP00000352035.2

Frequencies

GnomAD3 genomes

AF:

0.0000131

AC:

AN:

152252

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00

Gnomad ASJ

AF:

0.000288

Gnomad EAS

AF:

0.00

Gnomad SAS

AF:

0.00

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.0000147

Gnomad OTH

AF:

0.00

GnomAD2 exomes

AF:

0.00

AC:

AN:

232148

AF XY:

0.00

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.00000550

AC:

AN:

1454688

Hom.:

Cov.:

AF XY:

0.00000553

AC XY:

AN XY:

723358

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

33406

American (AMR)

AF:

0.00

AC:

AN:

44326

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

25990

East Asian (EAS)

AF:

0.00

AC:

AN:

39494

South Asian (SAS)

AF:

0.00

AC:

AN:

85660

European-Finnish (FIN)

AF:

0.00

AC:

AN:

50146

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5760

European-Non Finnish (NFE)

AF:

0.00000721

AC:

AN:

1109826

Other (OTH)

AF:

0.00

AC:

AN:

60080

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.512

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:

0.0000131

AC:

AN:

152252

Hom.:

Cov.:

AF XY:

0.0000134

AC XY:

AN XY:

74390

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

41474

American (AMR)

AF:

0.00

AC:

AN:

15290

Ashkenazi Jewish (ASJ)

AF:

0.000288

AC:

AN:

3472

East Asian (EAS)

AF:

0.00

AC:

AN:

5192

South Asian (SAS)

AF:

0.00

AC:

AN:

4834

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10626

Middle Eastern (MID)

AF:

0.00

AC:

AN:

316

European-Non Finnish (NFE)

AF:

0.0000147

AC:

AN:

68042

Other (OTH)

AF:

0.00

AC:

AN:

2094

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.600

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:

0.0000189

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:1Benign:1Other:1

Revision: criteria provided, conflicting classifications

LINK: link

Submissions by phenotype

Developmental and epileptic encephalopathy

Uncertain:1

Dec 09, 2023

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This sequence change replaces serine, which is neutral and polar, with leucine, which is neutral and non-polar, at codon 855 of the KCNQ2 protein (p.Ser855Leu). This variant is present in population databases (rs12481082, gnomAD 0.0009%). This variant has not been reported in the literature in individuals affected with KCNQ2-related conditions. ClinVar contains an entry for this variant (Variation ID: 21780). 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.

not provided

Benign:1

Dec 18, 2020

GeneDx

Significance:Likely benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

The majority of missense variants in this gene are considered pathogenic (Stenson et al., 2014); In silico analysis, which includes protein predictors and evolutionary conservation, supports that this variant does not alter protein structure/function; Predicted to be within the C-terminal cytoplasmic domain; Has not been previously published as pathogenic or benign to our knowledge

Seizures, benign familial neonatal, 1

Other:1

GeneReviews

Significance:not provided

Review Status:no classification provided

Collection Method:literature only

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.22

BayesDel_addAF

Uncertain

0.046

BayesDel_noAF

Benign

-0.17

CADD

Uncertain

(source)

DANN

Uncertain

1.0

DEOGEN2

Benign

0.0

.;T;T;T;.;.

Eigen

Uncertain

0.33

Eigen_PC

Uncertain

0.25

FATHMM_MKL

Pathogenic

1.0

LIST_S2

Pathogenic

0.99

D;D;D;D;D;D

M_CAP

Pathogenic

0.31

MetaRNN

Uncertain

0.60

D;D;D;D;D;D

MetaSVM

Benign

-0.37

MutationAssessor

Benign

0.0

.;.;M;.;.;.

PhyloP100

7.9

PrimateAI

Pathogenic

0.83

PROVEAN

Benign

0.0

.;.;N;.;N;.

REVEL

Benign

0.0

Sift

Pathogenic

0.0

.;.;D;.;D;.

Sift4G

Uncertain

0.0020

D;.;D;D;D;D

Vest4

0.65

ClinPred

0.98

GERP RS

4.1

Varity_R

0.47

gMVP

0.70

Mutation Taster

=67/33

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

You must be logged in to view publications. This limit was set because tens of millions (!) of queries from AI bots are generated daily.

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