rs796052650

Variant summary

Our verdict is Pathogenic. Variant got 13 ACMG points: 13P and 0B. PM2PP2PP3_ModeratePP5_Very_Strong

The NM_172107.4(KCNQ2):​c.1639C>T​(p.Arg547Trp) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000685 in 1,459,140 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Likely pathogenic (★★).

Frequency

Genomes: not found (cov: 33)
Exomes 𝑓: 6.9e-7 ( 0 hom. )

Consequence

KCNQ2
NM_172107.4 missense

Scores

11
4
4

Clinical Significance

Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:5O:1

Conservation

PhyloP100: 0.0970
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]

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Pathogenic. Variant got 13 ACMG points.

PM2
Very rare variant in population databases, with high coverage;
PP2
Missense variant in the KCNQ2 gene, where missense mutations are typically associated with disease (based on misZ statistic). The gene has 319 curated pathogenic missense variants (we use a threshold of 10). The gene has 78 curated benign missense variants. Gene score misZ: 4.0411 (above the threshold of 3.09). Trascript score misZ: 3.6968 (above the threshold of 3.09). GenCC associations: The gene is linked to seizures, benign familial neonatal, 1, neonatal-onset developmental and epileptic encephalopathy, benign familial neonatal-infantile seizures, benign neonatal seizures, malignant migrating partial seizures of infancy, neonatal encephalopathy with non-epileptic myoclonus, complex neurodevelopmental disorder, seizures, benign familial neonatal, 2, developmental and epileptic encephalopathy, 7, benign familial infantile epilepsy.
PP3
MetaRNN computational evidence supports a deleterious effect, 0.893
PP5
Variant 20-63413574-G-A is Pathogenic according to our data. Variant chr20-63413574-G-A is described in ClinVar as [Likely_pathogenic]. Clinvar id is 205912.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr20-63413574-G-A is described in Lovd as [Likely_pathogenic].

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
KCNQ2NM_172107.4 linkc.1639C>T p.Arg547Trp missense_variant Exon 15 of 17 ENST00000359125.7 NP_742105.1 O43526-1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
KCNQ2ENST00000359125.7 linkc.1639C>T p.Arg547Trp missense_variant Exon 15 of 17 1 NM_172107.4 ENSP00000352035.2 O43526-1

Frequencies

GnomAD3 genomes
Cov.:
33
GnomAD4 exome
AF:
6.85e-7
AC:
1
AN:
1459140
Hom.:
0
Cov.:
32
AF XY:
0.00000138
AC XY:
1
AN XY:
725938
show subpopulations
Gnomad4 AFR exome
AF:
0.00
Gnomad4 AMR exome
AF:
0.00
Gnomad4 ASJ exome
AF:
0.00
Gnomad4 EAS exome
AF:
0.00
Gnomad4 SAS exome
AF:
0.00
Gnomad4 FIN exome
AF:
0.00
Gnomad4 NFE exome
AF:
9.00e-7
Gnomad4 OTH exome
AF:
0.00
GnomAD4 genome
Cov.:
33

ClinVar

Significance: Pathogenic/Likely pathogenic
Submissions summary: Pathogenic:5Other:1
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

not provided Pathogenic:4
Nov 01, 2017
CeGaT Center for Human Genetics Tuebingen
Significance: Pathogenic
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

Nov 06, 2024
GeneDx
Significance: Pathogenic
Review Status: criteria provided, single submitter
Collection Method: clinical testing

Not observed at significant frequency in large population cohorts (gnomAD); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; This variant is associated with the following publications: (PMID: 28717674, 29655203, 34474328, 35401395, 29455050, 27602407, 39141400, 23360469, 37593999, 38074073) -

Aug 14, 2024
Mayo Clinic Laboratories, Mayo Clinic
Significance: Likely pathogenic
Review Status: criteria provided, single submitter
Collection Method: clinical testing

PP1, PP2, PP3, PM2, PS4_moderate -

Sep 02, 2016
Center for Pediatric Genomic Medicine, Children's Mercy Hospital and Clinics
Significance: Likely pathogenic
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

Early infantile epileptic encephalopathy with suppression bursts Pathogenic:1
May 23, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance: Pathogenic
Review Status: criteria provided, single submitter
Collection Method: clinical testing

This sequence change replaces arginine, which is basic and polar, with tryptophan, which is neutral and slightly polar, at codon 547 of the KCNQ2 protein (p.Arg547Trp). This variant is not present in population databases (gnomAD no frequency). This missense change has been observed in individuals with benign familial neonatal-infantile seizures (PMID: 23360469, 29655203; Invitae). It has also been observed to segregate with disease in related individuals. ClinVar contains an entry for this variant (Variation ID: 205912). An algorithm developed to predict the effect of missense changes on protein structure and function (PolyPhen-2) suggests that this variant is likely to be disruptive. 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
AlphaMissense
Pathogenic
0.87
BayesDel_addAF
Pathogenic
0.47
D
BayesDel_noAF
Pathogenic
0.43
CADD
Benign
23
DANN
Uncertain
1.0
DEOGEN2
Uncertain
0.49
.;.;T;T;D;T;D;T;.;.;T
Eigen
Benign
-0.27
Eigen_PC
Benign
-0.38
FATHMM_MKL
Benign
0.66
D
LIST_S2
Uncertain
0.95
D;D;D;D;D;D;D;D;D;D;D
M_CAP
Pathogenic
0.97
D
MetaRNN
Pathogenic
0.89
D;D;D;D;D;D;D;D;D;D;D
MetaSVM
Pathogenic
1.0
D
MutationAssessor
Uncertain
2.6
.;.;.;.;.;.;M;.;.;.;.
PrimateAI
Pathogenic
0.89
D
PROVEAN
Pathogenic
-5.2
.;.;.;.;D;.;D;.;D;.;.
REVEL
Pathogenic
0.79
Sift
Pathogenic
0.0
.;.;.;.;D;.;D;.;D;.;.
Sift4G
Pathogenic
0.0010
D;D;D;D;D;.;D;D;D;D;D
Polyphen
1.0
D;.;.;.;.;.;D;.;D;D;.
Vest4
0.85
MutPred
0.69
.;.;.;.;.;.;Loss of MoRF binding (P = 0.0876);.;.;.;.;
MVP
0.97
MPC
1.6
ClinPred
1.0
D
GERP RS
-1.1
Varity_R
0.89
gMVP
0.96

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

LitVar

Below is the list of publications found by LitVar. It may be empty.

Other links and lift over

dbSNP: rs796052650; hg19: chr20-62044927; COSMIC: COSV60557310; COSMIC: COSV60557310; API