20-63446794-T-C
Position:
Variant summary
Our verdict is Pathogenic. Variant got 11 ACMG points: 11P and 0B. PM1PM2PM5PP2PP3_ModeratePP5_Moderate
The NM_172107.4(KCNQ2):c.340A>G(p.Thr114Ala) variant causes a missense change. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Pathogenic (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. T114I) has been classified as Likely pathogenic.
Frequency
Genomes: not found (cov: 32)
Consequence
KCNQ2
NM_172107.4 missense
NM_172107.4 missense
Scores
10
4
1
Clinical Significance
Conservation
PhyloP100: 4.89
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]
Genome browser will be placed here
ACMG classification
Classification made for transcript
Verdict is Pathogenic. Variant got 11 ACMG points.
PM1
In a hotspot region, there are 4 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 8 uncertain in NM_172107.4
PM2
Very rare variant in population databases, with high coverage;
PM5
Other missense variant is known to change same aminoacid residue: Variant chr20-63446793-G-A is described in ClinVar as [Likely_pathogenic]. Clinvar id is 369742.Status of the report is criteria_provided_single_submitter, 1 stars.
PP2
Missense variant where missense usually causes diseases, KCNQ2
PP3
MetaRNN computational evidence supports a deleterious effect, 0.914
PP5
Variant 20-63446794-T-C is Pathogenic according to our data. Variant chr20-63446794-T-C is described in ClinVar as [Pathogenic]. Clinvar id is 369741.Status of the report is criteria_provided_single_submitter, 1 stars.
Transcripts
RefSeq
Gene | Transcript | HGVSc | HGVSp | Effect | #exon/exons | MANE | UniProt |
---|---|---|---|---|---|---|---|
KCNQ2 | NM_172107.4 | c.340A>G | p.Thr114Ala | missense_variant | 2/17 | ENST00000359125.7 |
Ensembl
Gene | Transcript | HGVSc | HGVSp | Effect | #exon/exons | TSL | MANE | Appris | UniProt |
---|---|---|---|---|---|---|---|---|---|
KCNQ2 | ENST00000359125.7 | c.340A>G | p.Thr114Ala | missense_variant | 2/17 | 1 | NM_172107.4 | A1 |
Frequencies
GnomAD3 genomes Cov.: 32
GnomAD3 genomes
Cov.:
32
GnomAD4 exome Cov.: 32
GnomAD4 exome
Cov.:
32
GnomAD4 genome Cov.: 32
GnomAD4 genome
Cov.:
32
ClinVar
Significance: Pathogenic
Submissions summary: Pathogenic:1Other:1
Revision: criteria provided, single submitter
LINK: link
Submissions by phenotype
Early infantile epileptic encephalopathy with suppression bursts Pathogenic:1
Pathogenic, criteria provided, single submitter | clinical testing | Invitae | Oct 16, 2023 | This sequence change replaces threonine, which is neutral and polar, with alanine, which is neutral and non-polar, at codon 114 of the KCNQ2 protein (p.Thr114Ala). This variant is not present in population databases (gnomAD no frequency). This missense change has been observed in individuals with KCNQ2-related conditions (PMID: 25982755; Invitae). ClinVar contains an entry for this variant (Variation ID: 369741). Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is expected to disrupt KCNQ2 protein function. This variant disrupts the p.Thr114 amino acid residue in KCNQ2. Other variant(s) that disrupt this residue have been determined to be pathogenic (PMID: 22926866). This suggests that this residue is clinically significant, and that variants that disrupt this residue are likely to be disease-causing. For these reasons, this variant has been classified as Pathogenic. - |
Seizures, benign familial neonatal, 1 Other:1
not provided, no classification provided | literature only | GeneReviews | - | BFNE (benign familial neonatal epilepsy) with later seizure recurrence - |
Computational scores
Source:
Name
Calibrated prediction
Score
Prediction
AlphaMissense
Pathogenic
BayesDel_addAF
Pathogenic
D
BayesDel_noAF
Pathogenic
CADD
Pathogenic
DANN
Uncertain
Eigen
Uncertain
Eigen_PC
Uncertain
FATHMM_MKL
Pathogenic
D
LIST_S2
Pathogenic
D;D;D;D;D;D;D;D;D
M_CAP
Pathogenic
D
MetaRNN
Pathogenic
D;D;D;D;D;D;D;D;D
MetaSVM
Pathogenic
D
MutationAssessor
Uncertain
M;.;.;.;.;M;M;M;M
MutationTaster
Benign
D;D;D;D;D;D;D;D;D;D;D;D
PrimateAI
Pathogenic
T
Sift4G
Pathogenic
D;D;D;D;D;D;D;D;D
Polyphen
D;.;.;.;.;D;D;D;.
Vest4
MutPred
Gain of helix (P = 0.0325);Gain of helix (P = 0.0325);Gain of helix (P = 0.0325);Gain of helix (P = 0.0325);Gain of helix (P = 0.0325);Gain of helix (P = 0.0325);Gain of helix (P = 0.0325);Gain of helix (P = 0.0325);Gain of helix (P = 0.0325);
MVP
MPC
1.5
ClinPred
D
GERP RS
Varity_R
gMVP
Splicing
Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
Details are displayed if max score is > 0.2
Find out detailed SpliceAI scores and Pangolin per-transcript scores at