rs199942237

Variant summary

Our verdict is Benign. The variant received -10 ACMG points: 0P and 10B. BP4_ModerateBP6_Very_Strong

The NM_004519.4(KCNQ3):​c.1964C>T​(p.Thr655Met) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000283 in 1,613,950 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 14/22 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Likely benign (★★). Synonymous variant affecting the same amino acid position (i.e. T655T) has been classified as Likely benign.

Frequency

Genomes: 𝑓 0.00018 ( 0 hom., cov: 33)
Exomes 𝑓: 0.00029 ( 0 hom. )

Consequence

KCNQ3
NM_004519.4 missense

Scores

2
1
13

Clinical Significance

Likely benign criteria provided, multiple submitters, no conflicts B:4

Conservation

PhyloP100: 3.10

Publications

9 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: Benign. The variant received -10 ACMG points.

BP4
Computational evidence support a benign effect (MetaRNN=0.25254658).
BP6
Variant 8-132129917-G-A is Benign according to our data. Variant chr8-132129917-G-A is described in ClinVar as Likely_benign. ClinVar VariationId is 378036.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
KCNQ3NM_004519.4 linkc.1964C>T p.Thr655Met missense_variant Exon 15 of 15 ENST00000388996.10 NP_004510.1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
KCNQ3ENST00000388996.10 linkc.1964C>T p.Thr655Met missense_variant Exon 15 of 15 1 NM_004519.4 ENSP00000373648.3

Frequencies

GnomAD3 genomes
AF:
0.000184
AC:
28
AN:
152068
Hom.:
0
Cov.:
33
show subpopulations
Gnomad AFR
AF:
0.000121
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.000131
Gnomad ASJ
AF:
0.00
Gnomad EAS
AF:
0.000193
Gnomad SAS
AF:
0.00
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.000294
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.000215
AC:
54
AN:
251482
AF XY:
0.000250
show subpopulations
Gnomad AFR exome
AF:
0.0000615
Gnomad AMR exome
AF:
0.0000867
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.0000544
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.000378
Gnomad OTH exome
AF:
0.000326
GnomAD4 exome
AF:
0.000293
AC:
429
AN:
1461882
Hom.:
0
Cov.:
32
AF XY:
0.000296
AC XY:
215
AN XY:
727246
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33480
American (AMR)
AF:
0.000179
AC:
8
AN:
44724
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26136
East Asian (EAS)
AF:
0.000176
AC:
7
AN:
39700
South Asian (SAS)
AF:
0.0000927
AC:
8
AN:
86258
European-Finnish (FIN)
AF:
0.0000187
AC:
1
AN:
53418
Middle Eastern (MID)
AF:
0.000173
AC:
1
AN:
5766
European-Non Finnish (NFE)
AF:
0.000341
AC:
379
AN:
1112004
Other (OTH)
AF:
0.000414
AC:
25
AN:
60396
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.477
Heterozygous variant carriers
0
28
56
84
112
140
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
20
40
60
80
100
<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:
0.000184
AC:
28
AN:
152068
Hom.:
0
Cov.:
33
AF XY:
0.000215
AC XY:
16
AN XY:
74276
show subpopulations
African (AFR)
AF:
0.000121
AC:
5
AN:
41382
American (AMR)
AF:
0.000131
AC:
2
AN:
15262
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3466
East Asian (EAS)
AF:
0.000193
AC:
1
AN:
5182
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4820
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10604
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.000294
AC:
20
AN:
68030
Other (OTH)
AF:
0.00
AC:
0
AN:
2094
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.491
Heterozygous variant carriers
0
2
3
5
6
8
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:
0.000294
Hom.:
0
Bravo
AF:
0.000189
ExAC
AF:
0.000181
AC:
22
EpiCase
AF:
0.000436
EpiControl
AF:
0.000474

ClinVar

Significance: Likely benign
Submissions summary: Benign:4
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

not provided Benign:2
Aug 01, 2023
CeGaT Center for Human Genetics Tuebingen
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

KCNQ3: BS2

Jul 15, 2019
GeneDx
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Inborn genetic diseases Benign:1
Aug 18, 2022
Ambry Genetics
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This alteration is classified as likely benign based on a combination of the following: seen in unaffected individuals, population frequency, intact protein function, lack of segregation with disease, co-occurrence, RNA analysis, in silico models, amino acid conservation, lack of disease association in case-control studies, and/or the mechanism of disease or impacted region is inconsistent with a known cause of pathogenicity.

Benign neonatal seizures Benign:1
Jan 13, 2025
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.087
BayesDel_addAF
Benign
-0.14
T
BayesDel_noAF
Benign
-0.12
CADD
Benign
16
DANN
Benign
0.95
DEOGEN2
Benign
0.28
T;.;.;.;.
Eigen
Benign
-0.19
Eigen_PC
Benign
-0.21
LIST_S2
Benign
0.80
T;T;T;T;T
M_CAP
Pathogenic
0.37
D
MetaRNN
Benign
0.25
T;T;T;T;T
MetaSVM
Pathogenic
0.98
D
MutationAssessor
Benign
1.8
L;.;.;.;.
PhyloP100
3.1
PrimateAI
Benign
0.29
T
PROVEAN
Benign
0.13
N;.;N;N;.
Sift
Benign
0.049
D;.;D;D;.
Sift4G
Uncertain
0.056
T;T;T;T;.
Vest4
0.053
ClinPred
0.046
T
GERP RS
3.9
Varity_R
0.036
gMVP
0.31
Mutation Taster
=93/7
polymorphism

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

Other links and lift over

dbSNP: rs199942237; hg19: chr8-133142164; COSMIC: COSV66483589; API