rs146492238

Variant summary

Our verdict is Benign. The variant received -19 ACMG points: 1P and 20B. PP2BP4_StrongBP6_Very_StrongBS1BS2

The NM_172107.4(KCNQ2):​c.1348G>A​(p.Val450Met) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0011 in 1,605,360 control chromosomes in the GnomAD database, including 11 homozygotes. In-silico tool predicts a benign outcome for this variant. 14/22 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Likely benign (★★).

Frequency

Genomes: 𝑓 0.00093 ( 2 hom., cov: 32)
Exomes 𝑓: 0.0011 ( 9 hom. )

Consequence

KCNQ2
NM_172107.4 missense

Scores

1
3
15

Clinical Significance

Benign/Likely benign criteria provided, multiple submitters, no conflicts B:9

Conservation

PhyloP100: 1.05

Publications

8 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

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Benign. The variant received -19 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.
BP4
Computational evidence support a benign effect (MetaRNN=0.005745232).
BP6
Variant 20-63415080-C-T is Benign according to our data. Variant chr20-63415080-C-T is described in ClinVar as Benign/Likely_benign. ClinVar VariationId is 129332.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
BS1
Variant frequency is greater than expected in population nfe. GnomAd4 allele frequency = 0.000926 (141/152260) while in subpopulation NFE AF = 0.000559 (38/68024). AF 95% confidence interval is 0.000418. There are 2 homozygotes in GnomAd4. There are 62 alleles in the male GnomAd4 subpopulation. Median coverage is 32. This position passed quality control check.
BS2
High AC in GnomAd4 at 141 AD gene.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
KCNQ2NM_172107.4 linkc.1348G>A p.Val450Met missense_variant Exon 13 of 17 ENST00000359125.7 NP_742105.1 O43526-1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
KCNQ2ENST00000359125.7 linkc.1348G>A p.Val450Met missense_variant Exon 13 of 17 1 NM_172107.4 ENSP00000352035.2 O43526-1

Frequencies

GnomAD3 genomes
AF:
0.000927
AC:
141
AN:
152142
Hom.:
2
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.000193
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.000196
Gnomad ASJ
AF:
0.0256
Gnomad EAS
AF:
0.00
Gnomad SAS
AF:
0.00
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.000559
Gnomad OTH
AF:
0.00143
GnomAD2 exomes
AF:
0.00164
AC:
394
AN:
239962
AF XY:
0.00155
show subpopulations
Gnomad AFR exome
AF:
0.0000634
Gnomad AMR exome
AF:
0.0000870
Gnomad ASJ exome
AF:
0.0294
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.000750
Gnomad OTH exome
AF:
0.00133
GnomAD4 exome
AF:
0.00111
AC:
1618
AN:
1453100
Hom.:
9
Cov.:
35
AF XY:
0.00108
AC XY:
782
AN XY:
723304
show subpopulations
African (AFR)
AF:
0.0000896
AC:
3
AN:
33478
American (AMR)
AF:
0.000157
AC:
7
AN:
44720
Ashkenazi Jewish (ASJ)
AF:
0.0273
AC:
714
AN:
26128
East Asian (EAS)
AF:
0.0000504
AC:
2
AN:
39696
South Asian (SAS)
AF:
0.000162
AC:
14
AN:
86258
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
44848
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5768
European-Non Finnish (NFE)
AF:
0.000666
AC:
740
AN:
1111878
Other (OTH)
AF:
0.00229
AC:
138
AN:
60326
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.492
Heterozygous variant carriers
0
112
224
337
449
561
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Exome Hom
Variant carriers
0
44
88
132
176
220
<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:
0.000926
AC:
141
AN:
152260
Hom.:
2
Cov.:
32
AF XY:
0.000833
AC XY:
62
AN XY:
74430
show subpopulations
African (AFR)
AF:
0.000193
AC:
8
AN:
41550
American (AMR)
AF:
0.000196
AC:
3
AN:
15310
Ashkenazi Jewish (ASJ)
AF:
0.0256
AC:
89
AN:
3470
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5148
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4828
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10612
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
294
European-Non Finnish (NFE)
AF:
0.000559
AC:
38
AN:
68024
Other (OTH)
AF:
0.00142
AC:
3
AN:
2114
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.516
Heterozygous variant carriers
0
8
17
25
34
42
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Genome Het
Genome Hom
Variant carriers
0
2
4
6
8
10
<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:
0.00194
Hom.:
10
Bravo
AF:
0.00112
ESP6500AA
AF:
0.000454
AC:
2
ESP6500EA
AF:
0.00175
AC:
15
ExAC
AF:
0.00126
AC:
153
EpiCase
AF:
0.00120
EpiControl
AF:
0.00124

ClinVar

Significance: Benign/Likely benign
Submissions summary: Benign:9
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

not provided Benign:4
Jan 01, 2024
CeGaT Center for Human Genetics Tuebingen
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

KCNQ2: BS1 -

-
Clinical Genetics DNA and cytogenetics Diagnostics Lab, Erasmus MC, Erasmus Medical Center
Significance:Likely benign
Review Status:no assertion criteria provided
Collection Method:clinical testing

- -

Jun 17, 2019
GeneDx
Significance:Benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

-
Genome Diagnostics Laboratory, University Medical Center Utrecht
Significance:Likely benign
Review Status:no assertion criteria provided
Collection Method:clinical testing

- -

not specified Benign:2
Dec 13, 2016
Eurofins Ntd Llc (ga)
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Oct 11, 2021
Genetic Services Laboratory, University of Chicago
Significance:Benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

KCNQ2-related disorder Benign:1
Sep 10, 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
Sep 29, 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
Jan 25, 2025
Labcorp Genetics (formerly Invitae), Labcorp
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
Benign
0.082
BayesDel_addAF
Benign
-0.21
T
BayesDel_noAF
Benign
-0.17
CADD
Benign
17
DANN
Uncertain
0.99
DEOGEN2
Benign
0.29
.;.;T;T;T;T;T;T;.;.
Eigen
Benign
-0.36
Eigen_PC
Benign
-0.26
FATHMM_MKL
Benign
0.54
D
LIST_S2
Benign
0.83
T;T;T;T;T;T;T;T;T;T
M_CAP
Pathogenic
0.30
D
MetaRNN
Benign
0.0057
T;T;T;T;T;T;T;T;T;T
MetaSVM
Uncertain
0.57
D
MutationAssessor
Benign
1.4
.;.;.;.;.;.;L;.;.;.
PhyloP100
1.1
PrimateAI
Uncertain
0.61
T
PROVEAN
Benign
0.12
.;.;.;.;N;.;N;.;N;.
REVEL
Benign
0.27
Sift
Benign
0.18
.;.;.;.;T;.;T;.;T;.
Sift4G
Benign
0.15
T;T;T;T;T;.;T;T;T;T
Polyphen
0.094
B;.;.;.;.;.;B;.;B;P
Vest4
0.18
MVP
0.57
MPC
0.64
ClinPred
0.0075
T
GERP RS
3.3
PromoterAI
0.0097
Neutral
Varity_R
0.045
gMVP
0.12
Mutation Taster
=99/1
polymorphism

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

Other links and lift over

dbSNP: rs146492238; hg19: chr20-62046433; COSMIC: COSV105236751; COSMIC: COSV105236751; API