rs1381851622

Variant summary

Our verdict is Uncertain significance. The variant received 4 ACMG points: 4P and 0B. PM1PP3_Moderate

The NM_004519.4(KCNQ3):​c.1000G>A​(p.Ala334Thr) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000643 in 1,399,672 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 Uncertain significance (★★).

Frequency

Genomes: not found (cov: 32)
Exomes 𝑓: 0.0000064 ( 0 hom. )

Consequence

KCNQ3
NM_004519.4 missense

Scores

13
4
2

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts P:1U:2

Conservation

PhyloP100: 7.90

Publications

3 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 4 ACMG points.

PM1
In a hotspot region, there are 4 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 1 benign, 8 uncertain in NM_004519.4
PP3
MetaRNN computational evidence supports a deleterious effect, 0.851

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
KCNQ3NM_004519.4 linkc.1000G>A p.Ala334Thr missense_variant Exon 6 of 15 ENST00000388996.10 NP_004510.1 O43525-1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
KCNQ3ENST00000388996.10 linkc.1000G>A p.Ala334Thr missense_variant Exon 6 of 15 1 NM_004519.4 ENSP00000373648.3 O43525-1

Frequencies

GnomAD3 genomes
Cov.:
32
GnomAD2 exomes
AF:
0.0000190
AC:
3
AN:
157748
AF XY:
0.0000241
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.0000402
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.0000649
Gnomad NFE exome
AF:
0.0000163
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.00000643
AC:
9
AN:
1399672
Hom.:
0
Cov.:
31
AF XY:
0.00000579
AC XY:
4
AN XY:
690426
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
31606
American (AMR)
AF:
0.0000279
AC:
1
AN:
35802
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
25204
East Asian (EAS)
AF:
0.00
AC:
0
AN:
35762
South Asian (SAS)
AF:
0.00
AC:
0
AN:
79244
European-Finnish (FIN)
AF:
0.0000608
AC:
3
AN:
49330
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5542
European-Non Finnish (NFE)
AF:
0.00000463
AC:
5
AN:
1079172
Other (OTH)
AF:
0.00
AC:
0
AN:
58010
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.486
Heterozygous variant carriers
0
1
2
3
4
5
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
Cov.:
32
Alfa
AF:
0.00
Hom.:
0
Bravo
AF:
0.00000756

ClinVar

Significance: Uncertain significance
Submissions summary: Pathogenic:1Uncertain:2
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Self-limited epilepsy with centrotemporal spikes Pathogenic:1
Jan 01, 2017
Bioinformatics Core, Luxembourg Center for Systems Biomedicine
Significance:Pathogenic
Review Status:no assertion criteria provided
Collection Method:case-control

CAADphred>15 -

Inborn genetic diseases Uncertain:1
Jul 19, 2018
Ambry Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Benign neonatal seizures Uncertain:1
Oct 29, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces alanine, which is neutral and non-polar, with threonine, which is neutral and polar, at codon 334 of the KCNQ3 protein (p.Ala334Thr). The frequency data for this variant in the population databases is considered unreliable, as metrics indicate poor data quality at this position in the gnomAD database. This missense change has been observed in individual(s) with Rolandic epilepsy (PMID: 29358611). ClinVar contains an entry for this variant (Variation ID: 433111). 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) has been performed for this missense variant. However, the output from this modeling did not meet the statistical confidence thresholds required to predict the impact of this variant on KCNQ3 protein function. 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. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Pathogenic
0.85
BayesDel_addAF
Pathogenic
0.24
D
BayesDel_noAF
Uncertain
0.11
CADD
Pathogenic
32
DANN
Pathogenic
1.0
DEOGEN2
Pathogenic
0.88
D;.;.;.;.
Eigen
Pathogenic
0.71
Eigen_PC
Pathogenic
0.71
FATHMM_MKL
Pathogenic
0.98
D
LIST_S2
Pathogenic
0.98
D;D;D;D;D
M_CAP
Pathogenic
0.49
D
MetaRNN
Pathogenic
0.85
D;D;D;D;D
MetaSVM
Pathogenic
1.1
D
MutationAssessor
Benign
1.9
L;.;.;.;.
PhyloP100
7.9
PrimateAI
Pathogenic
0.80
T
PROVEAN
Uncertain
-3.7
D;.;D;D;.
REVEL
Pathogenic
0.77
Sift
Uncertain
0.0010
D;.;D;D;.
Sift4G
Uncertain
0.0020
D;D;D;D;.
Polyphen
1.0
D;.;.;D;.
Vest4
0.56
MutPred
0.51
Gain of glycosylation at A334 (P = 0.0651);.;.;Gain of glycosylation at A334 (P = 0.0651);.;
MVP
0.91
MPC
2.0
ClinPred
0.97
D
GERP RS
5.0
Varity_R
0.72
gMVP
0.90
Mutation Taster
=43/57
disease causing

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: rs1381851622; hg19: chr8-133186530; COSMIC: COSV66464105; API