rs1057516115

Variant summary

Our verdict is Likely pathogenic. The variant received 6 ACMG points: 6P and 0B. PVS1_ModeratePM2PP5_Moderate

The NM_172107.4(KCNQ2):​c.1247+1G>A variant causes a splice donor, intron change. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. 3/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Pathogenic (★).

Frequency

Genomes: not found (cov: 32)
Exomes 𝑓: 0.0 ( 0 hom. )
Failed GnomAD Quality Control

Consequence

KCNQ2
NM_172107.4 splice_donor, intron

Scores

3
3
1
Splicing: ADA: 1.000
2

Clinical Significance

Pathogenic criteria provided, single submitter P:1O:1

Conservation

PhyloP100: 3.79

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: Likely_pathogenic. The variant received 6 ACMG points.

PVS1
Splicing +-2 bp (donor or acceptor) variant, product NOT destroyed by NMD, known LOF gene, truncates exone, which is 0.011454754 fraction of the gene. No cryptic splice site detected. Exon removal is inframe change.
PM2
Very rare variant in population databases, with high coverage;
PP5
Variant 20-63424176-C-T is Pathogenic according to our data. Variant chr20-63424176-C-T is described in ClinVar as Pathogenic. ClinVar VariationId is 369791.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
KCNQ2NM_172107.4 linkc.1247+1G>A splice_donor_variant, intron_variant Intron 11 of 16 ENST00000359125.7 NP_742105.1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
KCNQ2ENST00000359125.7 linkc.1247+1G>A splice_donor_variant, intron_variant Intron 11 of 16 1 NM_172107.4 ENSP00000352035.2

Frequencies

GnomAD3 genomes
Cov.:
32
GnomAD2 exomes
AF:
0.00
AC:
0
AN:
164364
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
Data not reliable, filtered out with message: AC0
AF:
0.00
AC:
0
AN:
1404090
Hom.:
0
Cov.:
31
AF XY:
0.00
AC XY:
0
AN XY:
692832
African (AFR)
AF:
0.00
AC:
0
AN:
32224
American (AMR)
AF:
0.00
AC:
0
AN:
35876
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
25194
East Asian (EAS)
AF:
0.00
AC:
0
AN:
36738
South Asian (SAS)
AF:
0.00
AC:
0
AN:
79560
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
49314
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5700
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
1081262
Other (OTH)
AF:
0.00
AC:
0
AN:
58222
GnomAD4 genome
Cov.:
32

ClinVar

Significance: Pathogenic
Submissions summary: Pathogenic:1Other:1
Revision: criteria provided, single submitter
LINK: link

Submissions by phenotype

Developmental and epileptic encephalopathy Pathogenic:1
Sep 06, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change affects a donor splice site in intron 11 of the KCNQ2 gene. It is expected to disrupt RNA splicing. Variants that disrupt the donor or acceptor splice site typically lead to a loss of protein function (PMID: 16199547), and loss-of-function variants in KCNQ2 are known to be pathogenic (PMID: 14534157, 23692823, 27779742). This variant is not present in population databases (gnomAD no frequency). Disruption of this splice site has been observed in individual(s) with autism spectrum disorder, benign familial neonatal-infantile seizures., and/or clinical features of KCNQ2-related conditions (PMID: 23849776, 25982755; internal data). In at least one individual the variant was observed to be de novo. ClinVar contains an entry for this variant (Variation ID: 369791). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site. For these reasons, this variant has been classified as Pathogenic. -

Seizures, benign familial neonatal, 1 Other:1
-
GeneReviews
Significance:not provided
Review Status:no classification provided
Collection Method:literature only

BFNE (benign familial neonatal epilepsy) -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
BayesDel_addAF
Pathogenic
0.63
D
BayesDel_noAF
Pathogenic
0.21
CADD
Pathogenic
28
DANN
Uncertain
0.99
Eigen
Pathogenic
0.83
Eigen_PC
Uncertain
0.62
FATHMM_MKL
Uncertain
0.91
D
PhyloP100
3.8
GERP RS
4.5
Mutation Taster
=0/100
disease causing (ClinVar)

Splicing

Name
Calibrated prediction
Score
Prediction
dbscSNV1_ADA
Pathogenic
1.0
dbscSNV1_RF
Pathogenic
0.93
SpliceAI score (max)
0.79
Details are displayed if max score is > 0.2
DS_DL_spliceai
0.79
Position offset: 1

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

Other links and lift over

dbSNP: rs1057516115; hg19: chr20-62055529; API