chr20-63438616-T-C

Variant summary

Our verdict is Benign. The variant received -20 ACMG points: 0P and 20B. BP4_StrongBP6_Very_StrongBS1BS2

The NM_172107.4(KCNQ2):​c.1023+9A>G variant causes a intron change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000124 in 1,612,468 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 Likely benign (★★).

Frequency

Genomes: 𝑓 0.000059 ( 0 hom., cov: 32)
Exomes 𝑓: 0.0000075 ( 0 hom. )

Consequence

KCNQ2
NM_172107.4 intron

Scores

2

Clinical Significance

Benign/Likely benign criteria provided, multiple submitters, no conflicts B:3

Conservation

PhyloP100: 0.609

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 -20 ACMG points.

BP4
Computational evidence support a benign effect (BayesDel_noAF=-0.87).
BP6
Variant 20-63438616-T-C is Benign according to our data. Variant chr20-63438616-T-C is described in ClinVar as [Likely_benign]. Clinvar id is 138018.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
BS1
Variant frequency is greater than expected in population amr. GnomAd4 allele frequency = 0.0000591 (9/152272) while in subpopulation AMR AF = 0.000588 (9/15304). AF 95% confidence interval is 0.000306. There are 0 homozygotes in GnomAd4. There are 5 alleles in the male GnomAd4 subpopulation. Median coverage is 32. This position passed quality control check.
BS2
High AC in GnomAd4 at 9 AD gene.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
KCNQ2NM_172107.4 linkc.1023+9A>G intron_variant Intron 7 of 16 ENST00000359125.7 NP_742105.1 O43526-1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
KCNQ2ENST00000359125.7 linkc.1023+9A>G intron_variant Intron 7 of 16 1 NM_172107.4 ENSP00000352035.2 O43526-1

Frequencies

GnomAD3 genomes
AF:
0.0000592
AC:
9
AN:
152154
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.00
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.000589
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:
0.00
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.0000199
AC:
5
AN:
250910
AF XY:
0.0000221
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.0000579
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:
0.000490
GnomAD4 exome
AF:
0.00000753
AC:
11
AN:
1460196
Hom.:
0
Cov.:
31
AF XY:
0.00000413
AC XY:
3
AN XY:
726492
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33442
American (AMR)
AF:
0.000134
AC:
6
AN:
44718
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26114
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39696
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86228
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
52894
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5768
European-Non Finnish (NFE)
AF:
9.00e-7
AC:
1
AN:
1110994
Other (OTH)
AF:
0.0000663
AC:
4
AN:
60342
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.489
Heterozygous variant carriers
0
1
3
4
6
7
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome 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
GnomAD4 genome
AF:
0.0000591
AC:
9
AN:
152272
Hom.:
0
Cov.:
32
AF XY:
0.0000671
AC XY:
5
AN XY:
74462
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41548
American (AMR)
AF:
0.000588
AC:
9
AN:
15304
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3472
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5180
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4820
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10624
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
294
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
68010
Other (OTH)
AF:
0.00
AC:
0
AN:
2108
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.514
Heterozygous variant carriers
0
1
2
2
3
4
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:
0.0000283
Hom.:
0
Bravo
AF:
0.000155

ClinVar

Significance: Benign/Likely benign
Submissions summary: Benign:3
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

not specified Benign:2
Feb 24, 2014
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. -

Feb 20, 2024
Athena Diagnostics
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Developmental and epileptic encephalopathy Benign:1
Nov 11, 2024
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
-0.87
CADD
Benign
0.060
DANN
Benign
0.34
PhyloP100
0.61

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: rs201787699; hg19: chr20-62069969; API