rs886041339

Variant summary

Our verdict is Pathogenic. The variant received 18 ACMG points: 18P and 0B. PVS1PM2PP5_Very_Strong

The NM_172107.4(KCNQ2):​c.1229delC​(p.Pro410ArgfsTer30) variant causes a frameshift change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000712 in 1,403,690 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Pathogenic (★★). Synonymous variant affecting the same amino acid position (i.e. P410P) has been classified as Likely benign. Variant results in nonsense mediated mRNA decay.

Frequency

Genomes: not found (cov: 32)
Exomes 𝑓: 7.1e-7 ( 0 hom. )

Consequence

KCNQ2
NM_172107.4 frameshift

Scores

Not classified

Clinical Significance

Pathogenic criteria provided, multiple submitters, no conflicts P:4

Conservation

PhyloP100: 1.09

Publications

1 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: G2P, Orphanet, Labcorp Genetics (formerly Invitae)
  • 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
  • undetermined early-onset epileptic encephalopathy
    Inheritance: AD Classification: DEFINITIVE Submitted by: ClinGen
  • 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: Pathogenic. The variant received 18 ACMG points.

PVS1
Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.
PM2
Very rare variant in population databases, with high coverage;
PP5
Variant 20-63424194-CG-C is Pathogenic according to our data. Variant chr20-63424194-CG-C is described in ClinVar as Pathogenic. ClinVar VariationId is 280043.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_172107.4. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Sel.
GeneTranscriptTagsHGVScHGVSpEffectExon RankProteinUniProt
KCNQ2
NM_172107.4
MANE Select
c.1229delCp.Pro410ArgfsTer30
frameshift
Exon 11 of 17NP_742105.1O43526-1
KCNQ2
NM_001382235.1
c.1229delCp.Pro410ArgfsTer12
frameshift
Exon 11 of 17NP_001369164.1A0A9L9PXL0
KCNQ2
NM_172106.3
c.1229delCp.Pro410ArgfsTer12
frameshift
Exon 11 of 16NP_742104.1O43526-2

Ensembl Transcripts

Sel.
GeneTranscriptTagsHGVScHGVSpEffectExon RankProteinUniProt
KCNQ2
ENST00000359125.7
TSL:1 MANE Select
c.1229delCp.Pro410ArgfsTer30
frameshift
Exon 11 of 17ENSP00000352035.2O43526-1
KCNQ2
ENST00000626839.2
TSL:1
c.1229delCp.Pro410ArgfsTer12
frameshift
Exon 11 of 16ENSP00000486706.1O43526-2
KCNQ2
ENST00000344462.8
TSL:1
c.1229delCp.Pro410ArgfsTer24
frameshift
Exon 11 of 16ENSP00000339611.4O43526-4

Frequencies

GnomAD3 genomes
Cov.:
32
GnomAD2 exomes
AF:
0.0000123
AC:
2
AN:
162634
AF XY:
0.00
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.00
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.0000816
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.0000157
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
7.12e-7
AC:
1
AN:
1403690
Hom.:
0
Cov.:
31
AF XY:
0.00
AC XY:
0
AN XY:
692618
show subpopulations
⚠️ The allele balance in gnomAD version 4 Exomes is significantly skewed from the expected value of 0.5.
African (AFR)
AF:
0.00
AC:
0
AN:
32198
American (AMR)
AF:
0.00
AC:
0
AN:
35852
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
25188
East Asian (EAS)
AF:
0.0000273
AC:
1
AN:
36688
South Asian (SAS)
AF:
0.00
AC:
0
AN:
79550
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
49222
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5698
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
1081110
Other (OTH)
AF:
0.00
AC:
0
AN:
58184
⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0), which strongly suggests a high chance of mosaicism in these individuals.
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.225
Heterozygous variant carriers
0
0
1
1
2
2
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
Cov.:
32

ClinVar

ClinVar submissions
Significance:Pathogenic
Revision:criteria provided, multiple submitters, no conflicts
View on ClinVar
Pathogenic
VUS
Benign
Condition
1
-
-
Developmental and epileptic encephalopathy (1)
1
-
-
Developmental and epileptic encephalopathy, 7 (1)
1
-
-
not provided (1)
1
-
-
Seizures, benign familial neonatal, 1 (1)

Computational scores

Source: dbNSFP v4.9

Name
Calibrated prediction
Score
Prediction
PhyloP100
1.1
Mutation Taster
=0/200
disease causing (ClinVar)

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.13
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: rs886041339; hg19: chr20-62055547; COSMIC: COSV60547846; COSMIC: COSV60547846; API