8-132480483-TCGCCGCCGC-TCGC

Variant summary

Our verdict is Uncertain significance. The variant received 1 ACMG points: 2P and 1B. PM2BP3

The NM_004519.4(KCNQ3):​c.44_49delGCGGCG​(p.Gly15_Gly16del) variant causes a disruptive inframe deletion change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000282 in 1,063,240 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★).

Frequency

Genomes: not found (cov: 32)
Exomes 𝑓: 0.0000028 ( 0 hom. )

Consequence

KCNQ3
NM_004519.4 disruptive_inframe_deletion

Scores

Not classified

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 0.858

Publications

0 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 1 ACMG points.

PM2
Very rare variant in population databases, with high coverage;
BP3
Nonframeshift variant in repetitive region in NM_004519.4

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
KCNQ3NM_004519.4 linkc.44_49delGCGGCG p.Gly15_Gly16del disruptive_inframe_deletion Exon 1 of 15 ENST00000388996.10 NP_004510.1 O43525-1
KCNQ3XM_047421769.1 linkc.44_49delGCGGCG p.Gly15_Gly16del disruptive_inframe_deletion Exon 1 of 15 XP_047277725.1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
KCNQ3ENST00000388996.10 linkc.44_49delGCGGCG p.Gly15_Gly16del disruptive_inframe_deletion Exon 1 of 15 1 NM_004519.4 ENSP00000373648.3 O43525-1
KCNQ3ENST00000519445.5 linkc.44_49delGCGGCG p.Gly15_Gly16del disruptive_inframe_deletion Exon 1 of 15 5 ENSP00000428790.1 E7ET42
KCNQ3ENST00000519589.1 linkn.-179_-174delGCGGCG upstream_gene_variant 2
KCNQ3ENST00000639358.1 linkn.-182_-177delGCGGCG upstream_gene_variant 5 ENSP00000492691.1 A0A1W2PRN8

Frequencies

GnomAD3 genomes
Cov.:
32
GnomAD4 exome
AF:
0.00000282
AC:
3
AN:
1063240
Hom.:
0
AF XY:
0.00000197
AC XY:
1
AN XY:
508208
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
21516
American (AMR)
AF:
0.00
AC:
0
AN:
7442
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
12476
East Asian (EAS)
AF:
0.00
AC:
0
AN:
23278
South Asian (SAS)
AF:
0.00
AC:
0
AN:
20818
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
20146
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
2834
European-Non Finnish (NFE)
AF:
0.00000328
AC:
3
AN:
913268
Other (OTH)
AF:
0.00
AC:
0
AN:
41462
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.475
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

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: Uncertain:1
Revision: criteria provided, single submitter
LINK: link

Submissions by phenotype

Benign neonatal seizures Uncertain:1
Jun 23, 2023
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

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. Experimental studies and prediction algorithms are not available or were not evaluated, and the functional significance of this variant is currently unknown. This variant has not been reported in the literature in individuals affected with KCNQ3-related conditions. This variant is not present in population databases (gnomAD no frequency). This variant, c.44_49del, results in the deletion of 2 amino acid(s) of the KCNQ3 protein (p.Gly15_Gly16del), but otherwise preserves the integrity of the reading frame. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
PhyloP100
0.86
Mutation Taster
=171/29
polymorphism

Splicing

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

Other links and lift over

dbSNP: rs981093917; hg19: chr8-133492730; API