NM_004519.4:c.1885G>A

Variant summary

Our verdict is Uncertain significance. The variant received 0 ACMG points: 1P and 1B. PP3BP6

The NM_004519.4(KCNQ3):​c.1885G>A​(p.Val629Ile) variant causes a missense, splice region change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000167 in 1,612,984 control chromosomes in the GnomAD database, with no homozygous occurrence. 2/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. V629L) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.000033 ( 0 hom., cov: 33)
Exomes 𝑓: 0.000015 ( 0 hom. )

Consequence

KCNQ3
NM_004519.4 missense, splice_region

Scores

5
11
3
Splicing: ADA: 0.9987
2

Clinical Significance

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

Conservation

PhyloP100: 7.37

Publications

4 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.

PP3
Splicing predictors support a deleterious effect. Scorers claiming Pathogenic: dbscSNV1_ADA, dbscSNV1_RF. No scorers claiming Uncertain. Scorers claiming Benign: max_spliceai.
BP6
Variant 8-132129996-C-T is Benign according to our data. Variant chr8-132129996-C-T is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 449145.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
KCNQ3NM_004519.4 linkc.1885G>A p.Val629Ile missense_variant, splice_region_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.1885G>A p.Val629Ile missense_variant, splice_region_variant Exon 15 of 15 1 NM_004519.4 ENSP00000373648.3

Frequencies

GnomAD3 genomes
AF:
0.0000329
AC:
5
AN:
152052
Hom.:
0
Cov.:
33
show subpopulations
Gnomad AFR
AF:
0.0000242
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.000131
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:
0.0000294
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.0000518
AC:
13
AN:
251010
AF XY:
0.0000295
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.000289
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:
0.000163
GnomAD4 exome
AF:
0.0000151
AC:
22
AN:
1460932
Hom.:
0
Cov.:
32
AF XY:
0.0000124
AC XY:
9
AN XY:
726768
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33466
American (AMR)
AF:
0.000291
AC:
13
AN:
44724
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26136
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39700
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86214
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53176
Middle Eastern (MID)
AF:
0.000193
AC:
1
AN:
5180
European-Non Finnish (NFE)
AF:
0.00000719
AC:
8
AN:
1112008
Other (OTH)
AF:
0.00
AC:
0
AN:
60328
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.466
Heterozygous variant carriers
0
2
4
7
9
11
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome 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
GnomAD4 genome
AF:
0.0000329
AC:
5
AN:
152052
Hom.:
0
Cov.:
33
AF XY:
0.0000269
AC XY:
2
AN XY:
74270
show subpopulations
African (AFR)
AF:
0.0000242
AC:
1
AN:
41366
American (AMR)
AF:
0.000131
AC:
2
AN:
15270
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3472
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5186
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4836
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10584
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.0000294
AC:
2
AN:
68020
Other (OTH)
AF:
0.00
AC:
0
AN:
2090
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.515
Heterozygous variant carriers
0
1
2
2
3
4
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.:
0
Bravo
AF:
0.0000680
ExAC
AF:
0.0000165
AC:
2
EpiCase
AF:
0.0000545
EpiControl
AF:
0.0000593

ClinVar

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

Submissions by phenotype

Benign neonatal seizures Uncertain:1
Oct 14, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces valine, which is neutral and non-polar, with isoleucine, which is neutral and non-polar, at codon 629 of the KCNQ3 protein (p.Val629Ile). This variant is present in population databases (rs185511111, gnomAD 0.03%). This missense change has been observed in individual(s) with clinical features of KCNQ3-related conditions (internal data). ClinVar contains an entry for this variant (Variation ID: 449145). 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. 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. -

Inborn genetic diseases Benign:1
Jun 30, 2021
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. -

not provided Benign:1
Jun 22, 2021
GeneDx
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
Uncertain
0.38
BayesDel_addAF
Uncertain
0.015
T
BayesDel_noAF
Uncertain
0.090
CADD
Pathogenic
29
DANN
Uncertain
1.0
DEOGEN2
Uncertain
0.72
D;.;.;.;.
Eigen
Pathogenic
0.70
Eigen_PC
Pathogenic
0.72
FATHMM_MKL
Pathogenic
0.99
D
LIST_S2
Uncertain
0.97
D;D;D;D;D
M_CAP
Uncertain
0.28
D
MetaRNN
Uncertain
0.72
D;D;D;D;D
MetaSVM
Pathogenic
1.1
D
MutationAssessor
Uncertain
2.8
M;.;.;.;.
PhyloP100
7.4
PrimateAI
Benign
0.33
T
PROVEAN
Benign
-0.91
N;.;N;N;.
REVEL
Pathogenic
0.74
Sift
Uncertain
0.0020
D;.;D;D;.
Sift4G
Uncertain
0.0070
D;D;D;D;.
Polyphen
0.98
D;.;.;D;.
Vest4
0.50
MutPred
0.65
Loss of disorder (P = 0.1022);.;.;.;.;
MVP
0.73
MPC
0.46
ClinPred
0.54
D
GERP RS
5.7
Varity_R
0.46
gMVP
0.51
Mutation Taster
=55/45
polymorphism

Splicing

Name
Calibrated prediction
Score
Prediction
dbscSNV1_ADA
Pathogenic
1.0
dbscSNV1_RF
Pathogenic
0.89
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: rs185511111; hg19: chr8-133142243; API