rs774206764

Variant summary

Our verdict is Likely benign. Variant got -3 ACMG points: 2P and 5B. PP2PP5BP4BS2

The NM_172107.4(KCNQ2):​c.2315C>T​(p.Pro772Leu) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000158 in 1,583,636 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 12/21 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

Frequency

Genomes: 𝑓 0.000026 ( 0 hom., cov: 34)
Exomes 𝑓: 0.000015 ( 0 hom. )

Consequence

KCNQ2
NM_172107.4 missense

Scores

2
17

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:1U:2

Conservation

PhyloP100: 1.49
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 Likely_benign. Variant got -3 ACMG points.

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.
PP5
Variant 20-63406948-G-A is Pathogenic according to our data. Variant chr20-63406948-G-A is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 530457.We mark this variant Likely_pathogenic, oryginal submissions are: {Likely_pathogenic=1, Uncertain_significance=2}.
BP4
Computational evidence support a benign effect (MetaRNN=0.0916633). . Strength limited to SUPPORTING due to the PP5.
BS2
High AC in GnomAdExome4 at 21 AD gene.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
KCNQ2NM_172107.4 linkc.2315C>T p.Pro772Leu missense_variant Exon 17 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.2315C>T p.Pro772Leu missense_variant Exon 17 of 17 1 NM_172107.4 ENSP00000352035.2 O43526-1

Frequencies

GnomAD3 genomes
AF:
0.0000263
AC:
4
AN:
152196
Hom.:
0
Cov.:
34
show subpopulations
Gnomad AFR
AF:
0.0000241
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.00
Gnomad ASJ
AF:
0.000288
Gnomad EAS
AF:
0.00
Gnomad SAS
AF:
0.000207
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.0000147
Gnomad OTH
AF:
0.00
GnomAD3 exomes
AF:
0.0000364
AC:
7
AN:
192192
Hom.:
0
AF XY:
0.0000377
AC XY:
4
AN XY:
106222
show subpopulations
Gnomad AFR exome
AF:
0.0000887
Gnomad AMR exome
AF:
0.0000330
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.0000661
Gnomad SAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.0000482
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000147
AC:
21
AN:
1431440
Hom.:
0
Cov.:
36
AF XY:
0.0000141
AC XY:
10
AN XY:
710220
show subpopulations
Gnomad4 AFR exome
AF:
0.00
Gnomad4 AMR exome
AF:
0.0000478
Gnomad4 ASJ exome
AF:
0.00
Gnomad4 EAS exome
AF:
0.0000260
Gnomad4 SAS exome
AF:
0.00
Gnomad4 FIN exome
AF:
0.00
Gnomad4 NFE exome
AF:
0.0000164
Gnomad4 OTH exome
AF:
0.00
GnomAD4 genome
AF:
0.0000263
AC:
4
AN:
152196
Hom.:
0
Cov.:
34
AF XY:
0.0000403
AC XY:
3
AN XY:
74352
show subpopulations
Gnomad4 AFR
AF:
0.0000241
Gnomad4 AMR
AF:
0.00
Gnomad4 ASJ
AF:
0.000288
Gnomad4 EAS
AF:
0.00
Gnomad4 SAS
AF:
0.000207
Gnomad4 FIN
AF:
0.00
Gnomad4 NFE
AF:
0.0000147
Gnomad4 OTH
AF:
0.00
Bravo
AF:
0.0000227
ExAC
AF:
0.0000336
AC:
4

ClinVar

Significance: Conflicting classifications of pathogenicity
Submissions summary: Pathogenic:1Uncertain:2
Revision: criteria provided, conflicting classifications
LINK: link

Submissions by phenotype

Early infantile epileptic encephalopathy with suppression bursts Pathogenic:1
Nov 21, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance: Likely pathogenic
Review Status: criteria provided, single submitter
Collection Method: clinical testing

This sequence change replaces proline, which is neutral and non-polar, with leucine, which is neutral and non-polar, at codon 772 of the KCNQ2 protein (p.Pro772Leu). This variant is present in population databases (rs774206764, gnomAD 0.006%). This missense change has been observed in individuals with clinical features of developmental and epileptic encephalopathy (internal data). ClinVar contains an entry for this variant (Variation ID: 530457). Invitae Evidence Modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) indicates that this missense variant is not expected to disrupt KCNQ2 protein function with a negative predictive value of 95%. In summary, the currently available evidence indicates that the variant is pathogenic, but additional data are needed to prove that conclusively. Therefore, this variant has been classified as Likely Pathogenic. -

not specified Uncertain:1
Oct 27, 2023
Women's Health and Genetics/Laboratory Corporation of America, LabCorp
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing

Variant summary: KCNQ2 c.2315C>T (p.Pro772Leu) results in a non-conservative amino acid change in the encoded protein sequence. Four of five in-silico tools predict a benign effect of the variant on protein function. The variant allele was found at a frequency of 3.6e-05 in 192192 control chromosomes (gnomAD). The available data on variant occurrences in the general population are insufficient to allow any conclusion about variant significance. c.2315C>T has been reported in the literature as a VUS in the heterozygous state in a setting of WES in an individual affected with epilepsy who also had other putatively pathogenic variants reported in epilepsy-related genes (Al Anazi_2022). This report does not provide unequivocal conclusions about association of the variant with KCNQ2-Related Disorders. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. The following publication has been ascertained in the context of this evaluation (PMID: 36539902). One submitter has cited a clinical-significance assessment for this variant to ClinVar after 2014 and has classified the variant as uncertain significance. Based on the evidence outlined above, the variant was classified as uncertain significance. -

not provided Uncertain:1
Jan 01, 2025
CeGaT Center for Human Genetics Tuebingen
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.071
BayesDel_addAF
Benign
-0.15
T
BayesDel_noAF
Benign
-0.25
CADD
Benign
14
DANN
Benign
0.85
DEOGEN2
Benign
0.0082
.;T;T;T;.;.
Eigen
Benign
-0.99
Eigen_PC
Benign
-1.0
FATHMM_MKL
Benign
0.24
N
LIST_S2
Benign
0.78
T;T;T;T;T;T
M_CAP
Uncertain
0.12
D
MetaRNN
Benign
0.092
T;T;T;T;T;T
MetaSVM
Benign
-1.1
T
MutationAssessor
Benign
0.69
.;.;N;.;.;.
PrimateAI
Uncertain
0.62
T
PROVEAN
Benign
-0.61
.;.;N;.;N;D
REVEL
Benign
0.038
Sift
Benign
0.73
.;.;T;.;T;T
Sift4G
Benign
0.70
T;.;T;T;T;T
Polyphen
0.49
P;.;P;.;P;B
Vest4
0.049
MVP
0.66
MPC
0.81
ClinPred
0.012
T
GERP RS
1.6
Varity_R
0.017
gMVP
0.20

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: rs774206764; hg19: chr20-62038301; COSMIC: COSV60546472; COSMIC: COSV60546472; API