8-132134369-G-T

Variant summary

Our verdict is Uncertain significance. The variant received 0 ACMG points: 0P and 0B.

The NM_004519.4(KCNQ3):​c.1720C>A​(p.Pro574Thr) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000477 in 1,612,832 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. P574S) has been classified as Likely benign.

Frequency

Genomes: 𝑓 0.000053 ( 0 hom., cov: 31)
Exomes 𝑓: 0.000047 ( 0 hom. )

Consequence

KCNQ3
NM_004519.4 missense

Scores

8
6
4

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:4

Conservation

PhyloP100: 9.32

Publications

27 publications found
Variant links:
Genes affected
KCNQ3 (HGNC:6297): (potassium voltage-gated channel subfamily Q member 3) This gene encodes a protein that functions in the regulation of neuronal excitability. The encoded protein forms an M-channel by associating with the products of the related KCNQ2 or KCNQ5 genes, which both encode integral membrane proteins. M-channel currents are inhibited by M1 muscarinic acetylcholine receptors and are activated by retigabine, a novel anti-convulsant drug. Defects in this gene are a cause of benign familial neonatal convulsions type 2 (BFNC2), also known as epilepsy, benign neonatal type 2 (EBN2). Alternative splicing of this gene results in multiple transcript variants. [provided by RefSeq, May 2014]
KCNQ3 Gene-Disease associations (from GenCC):
  • seizures, benign familial neonatal, 2
    Inheritance: AD Classification: STRONG, MODERATE Submitted by: Ambry Genetics, Labcorp Genetics (formerly Invitae)
  • benign familial infantile epilepsy
    Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
  • benign neonatal seizures
    Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
  • genetic developmental and epileptic encephalopathy
    Inheritance: AR Classification: LIMITED Submitted by: Ambry Genetics

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Uncertain_significance. The variant received 0 ACMG points.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_004519.4. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected
GeneTranscriptTagsHGVScHGVSpEffectExon RankProteinUniProt
KCNQ3
NM_004519.4
MANE Select
c.1720C>Ap.Pro574Thr
missense
Exon 13 of 15NP_004510.1
KCNQ3
NM_001204824.2
c.1360C>Ap.Pro454Thr
missense
Exon 13 of 15NP_001191753.1

Ensembl Transcripts

Selected
GeneTranscriptTagsHGVScHGVSpEffectExon RankProteinUniProt
KCNQ3
ENST00000388996.10
TSL:1 MANE Select
c.1720C>Ap.Pro574Thr
missense
Exon 13 of 15ENSP00000373648.3
KCNQ3
ENST00000519445.5
TSL:5
c.1720C>Ap.Pro574Thr
missense
Exon 13 of 15ENSP00000428790.1
KCNQ3
ENST00000521134.6
TSL:2
c.1360C>Ap.Pro454Thr
missense
Exon 13 of 15ENSP00000429799.1

Frequencies

GnomAD3 genomes
AF:
0.0000526
AC:
8
AN:
152092
Hom.:
0
Cov.:
31
show subpopulations
Gnomad AFR
AF:
0.0000241
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.00
Gnomad ASJ
AF:
0.00
Gnomad EAS
AF:
0.00
Gnomad SAS
AF:
0.00
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.000103
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.0000119
AC:
3
AN:
251432
AF XY:
0.0000221
show subpopulations
Gnomad AFR exome
AF:
0.0000615
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:
0.0000176
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000472
AC:
69
AN:
1460740
Hom.:
0
Cov.:
30
AF XY:
0.0000440
AC XY:
32
AN XY:
726766
show subpopulations
African (AFR)
AF:
0.0000896
AC:
3
AN:
33468
American (AMR)
AF:
0.00
AC:
0
AN:
44722
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26132
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39692
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86216
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53414
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5754
European-Non Finnish (NFE)
AF:
0.0000585
AC:
65
AN:
1110988
Other (OTH)
AF:
0.0000166
AC:
1
AN:
60354
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.445
Heterozygous variant carriers
0
4
8
12
16
20
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
4
8
12
16
20
<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
AF:
0.0000526
AC:
8
AN:
152092
Hom.:
0
Cov.:
31
AF XY:
0.0000269
AC XY:
2
AN XY:
74286
show subpopulations
African (AFR)
AF:
0.0000241
AC:
1
AN:
41432
American (AMR)
AF:
0.00
AC:
0
AN:
15264
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3468
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5164
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4814
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10606
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.000103
AC:
7
AN:
68026
Other (OTH)
AF:
0.00
AC:
0
AN:
2090
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.463
Heterozygous variant carriers
0
1
1
2
2
3
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Genome 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
Alfa
AF:
0.00
Hom.:
1
ExAC
AF:
0.00000824
AC:
1
EpiCase
AF:
0.0000545
EpiControl
AF:
0.00

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:4
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Inborn genetic diseases Uncertain:1
Feb 20, 2017
Ambry Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Benign neonatal seizures Uncertain:1
May 21, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces proline, which is neutral and non-polar, with threonine, which is neutral and polar, at codon 574 of the KCNQ3 protein (p.Pro574Thr). This variant is present in population databases (rs74582884, gnomAD 0.004%). This missense change has been observed in individual(s) with idiopathic epilepsy (PMID: 21703448). ClinVar contains an entry for this variant (Variation ID: 205976). 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 not expected to disrupt KCNQ3 protein function with a negative predictive value of 80%. In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance.

Seizures, benign familial neonatal, 2 Uncertain:1
Oct 09, 2023
Zotz-Klimas Genetics Lab, MVZ Zotz Klimas
Significance:Uncertain significance
Review Status:no assertion criteria provided
Collection Method:clinical testing

not provided Uncertain:1
Mar 12, 2024
GeneDx
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Previously identified in a patient with idiopathic epilepsy and was not detected in controls; however, no additional information was provided (PMID: 21703448); In silico analysis supports that this missense variant does not alter protein structure/function; Not observed at significant frequency in large population cohorts (gnomAD); This variant is associated with the following publications: (PMID: 28488083, 21703448)

Computational scores

Source: dbNSFP v4.9

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.26
BayesDel_addAF
Pathogenic
0.39
D
BayesDel_noAF
Pathogenic
0.50
CADD
Pathogenic
31
DANN
Uncertain
1.0
DEOGEN2
Uncertain
0.79
D
Eigen
Pathogenic
0.82
Eigen_PC
Pathogenic
0.82
FATHMM_MKL
Pathogenic
1.0
D
LIST_S2
Uncertain
0.95
D
M_CAP
Pathogenic
0.41
D
MetaRNN
Uncertain
0.74
D
MetaSVM
Pathogenic
1.1
D
MutationAssessor
Uncertain
2.5
M
PhyloP100
9.3
PrimateAI
Uncertain
0.74
T
PROVEAN
Benign
-1.4
N
REVEL
Pathogenic
0.75
Sift
Benign
0.12
T
Sift4G
Benign
0.12
T
Polyphen
1.0
D
Vest4
0.70
MutPred
0.45
Loss of phosphorylation at T573 (P = 0.0619)
MVP
0.88
MPC
0.53
ClinPred
0.90
D
GERP RS
5.5
Varity_R
0.25
gMVP
0.63
Mutation Taster
=5/95
disease causing

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.15
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: rs74582884; hg19: chr8-133146616; API