rs369438374

Variant summary

Our verdict is Benign. The variant received -14 ACMG points: 0P and 14B. BP4_StrongBP6BP7BS1BS2

The NM_172107.4(KCNQ2):​c.1827C>T​(p.Ala609Ala) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000759 in 1,607,862 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Synonymous variant affecting the same amino acid position (i.e. A609A) has been classified as Likely benign.

Frequency

Genomes: 𝑓 0.00047 ( 0 hom., cov: 33)
Exomes 𝑓: 0.00079 ( 0 hom. )

Consequence

KCNQ2
NM_172107.4 synonymous

Scores

2

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:1B:4

Conservation

PhyloP100: -11.0

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

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Benign. The variant received -14 ACMG points.

BP4
Computational evidence support a benign effect (BayesDel_noAF=-0.95).
BP6
Variant 20-63408473-G-A is Benign according to our data. Variant chr20-63408473-G-A is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 138028.
BP7
Synonymous conserved (PhyloP=-11 with no splicing effect.
BS1
Variant frequency is greater than expected in population sas. GnomAd4 allele frequency = 0.000473 (72/152240) while in subpopulation SAS AF = 0.00104 (5/4822). AF 95% confidence interval is 0.000638. There are 0 homozygotes in GnomAd4. There are 35 alleles in the male GnomAd4 subpopulation. Median coverage is 33. This position passed quality control check.
BS2
High AC in GnomAd4 at 72 AD gene.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
KCNQ2NM_172107.4 linkc.1827C>T p.Ala609Ala synonymous_variant Exon 16 of 17 ENST00000359125.7 NP_742105.1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
KCNQ2ENST00000359125.7 linkc.1827C>T p.Ala609Ala synonymous_variant Exon 16 of 17 1 NM_172107.4 ENSP00000352035.2

Frequencies

GnomAD3 genomes
AF:
0.000473
AC:
72
AN:
152122
Hom.:
0
Cov.:
33
show subpopulations
Gnomad AFR
AF:
0.000241
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.0000654
Gnomad ASJ
AF:
0.000288
Gnomad EAS
AF:
0.00
Gnomad SAS
AF:
0.00104
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.000809
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.000499
AC:
118
AN:
236494
AF XY:
0.000543
show subpopulations
Gnomad AFR exome
AF:
0.000135
Gnomad AMR exome
AF:
0.0000893
Gnomad ASJ exome
AF:
0.000515
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.000857
Gnomad OTH exome
AF:
0.000522
GnomAD4 exome
AF:
0.000789
AC:
1148
AN:
1455622
Hom.:
0
Cov.:
31
AF XY:
0.000778
AC XY:
563
AN XY:
723856
show subpopulations
African (AFR)
AF:
0.0000599
AC:
2
AN:
33402
American (AMR)
AF:
0.0000678
AC:
3
AN:
44224
Ashkenazi Jewish (ASJ)
AF:
0.000346
AC:
9
AN:
25992
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39416
South Asian (SAS)
AF:
0.000410
AC:
35
AN:
85400
European-Finnish (FIN)
AF:
0.0000392
AC:
2
AN:
51080
Middle Eastern (MID)
AF:
0.000174
AC:
1
AN:
5760
European-Non Finnish (NFE)
AF:
0.000932
AC:
1035
AN:
1110196
Other (OTH)
AF:
0.00101
AC:
61
AN:
60152
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.497
Heterozygous variant carriers
0
73
147
220
294
367
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
42
84
126
168
210
<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:
0.000473
AC:
72
AN:
152240
Hom.:
0
Cov.:
33
AF XY:
0.000470
AC XY:
35
AN XY:
74428
show subpopulations
African (AFR)
AF:
0.000241
AC:
10
AN:
41552
American (AMR)
AF:
0.0000654
AC:
1
AN:
15300
Ashkenazi Jewish (ASJ)
AF:
0.000288
AC:
1
AN:
3470
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5166
South Asian (SAS)
AF:
0.00104
AC:
5
AN:
4822
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10620
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
294
European-Non Finnish (NFE)
AF:
0.000809
AC:
55
AN:
67990
Other (OTH)
AF:
0.00
AC:
0
AN:
2114
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.510
Heterozygous variant carriers
0
4
8
11
15
19
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Genome Het
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:
0.000692
Hom.:
0
Bravo
AF:
0.000374
Asia WGS
AF:
0.000866
AC:
3
AN:
3478

ClinVar

Significance: Conflicting classifications of pathogenicity
Submissions summary: Uncertain:1Benign:4
Revision: criteria provided, conflicting classifications
LINK: link

Submissions by phenotype

not provided Uncertain:1Benign:1
Aug 01, 2024
CeGaT Center for Human Genetics Tuebingen
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

KCNQ2: BP4, BP7 -

Nov 12, 2015
Eurofins Ntd Llc (ga)
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

not specified Benign:1
Jan 31, 2013
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. -

Inborn genetic diseases Benign:1
Jan 22, 2018
Ambry Genetics
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This alteration is classified as likely 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 30, 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
BayesDel_noAF
Benign
-0.95
CADD
Benign
0.30
DANN
Benign
0.69
PhyloP100
-11
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: rs369438374; hg19: chr20-62039826; COSMIC: COSV60550055; COSMIC: COSV60550055; API