rs35538317

Variant summary

Our verdict is Benign. The variant received -21 ACMG points: 0P and 21B. BP4_StrongBP6_Very_StrongBP7BS1BS2

The NM_004519.4(KCNQ3):​c.1551C>T​(p.Ala517Ala) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00144 in 1,600,860 control chromosomes in the GnomAD database, including 31 homozygotes. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Likely benign (★★).

Frequency

Genomes: 𝑓 0.0071 ( 15 hom., cov: 32)
Exomes 𝑓: 0.00084 ( 16 hom. )

Consequence

KCNQ3
NM_004519.4 synonymous

Scores

2

Clinical Significance

Benign/Likely benign criteria provided, multiple submitters, no conflicts B:10

Conservation

PhyloP100: -2.09

Publications

2 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 -21 ACMG points.

BP4
Computational evidence support a benign effect (BayesDel_noAF=-0.71).
BP6
Variant 8-132140093-G-A is Benign according to our data. Variant chr8-132140093-G-A is described in ClinVar as Benign/Likely_benign. ClinVar VariationId is 129348.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
BP7
Synonymous conserved (PhyloP=-2.09 with no splicing effect.
BS1
Variant frequency is greater than expected in population afr. GnomAd4 allele frequency = 0.00706 (1075/152218) while in subpopulation AFR AF = 0.024 (998/41524). AF 95% confidence interval is 0.0228. There are 15 homozygotes in GnomAd4. There are 493 alleles in the male GnomAd4 subpopulation. Median coverage is 32. This position passed quality control check.
BS2
High Homozygotes in GnomAd4 at 15 AD,AR gene

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
KCNQ3NM_004519.4 linkc.1551C>T p.Ala517Ala synonymous_variant Exon 11 of 15 ENST00000388996.10 NP_004510.1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
KCNQ3ENST00000388996.10 linkc.1551C>T p.Ala517Ala synonymous_variant Exon 11 of 15 1 NM_004519.4 ENSP00000373648.3

Frequencies

GnomAD3 genomes
AF:
0.00707
AC:
1076
AN:
152100
Hom.:
15
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.0241
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.00334
Gnomad ASJ
AF:
0.00
Gnomad EAS
AF:
0.00
Gnomad SAS
AF:
0.000207
Gnomad FIN
AF:
0.0000942
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.000206
Gnomad OTH
AF:
0.00478
GnomAD2 exomes
AF:
0.00204
AC:
482
AN:
236358
AF XY:
0.00162
show subpopulations
Gnomad AFR exome
AF:
0.0250
Gnomad AMR exome
AF:
0.00141
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.0000554
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.000236
Gnomad OTH exome
AF:
0.00104
GnomAD4 exome
AF:
0.000844
AC:
1223
AN:
1448642
Hom.:
16
Cov.:
30
AF XY:
0.000771
AC XY:
555
AN XY:
719476
show subpopulations
African (AFR)
AF:
0.0269
AC:
894
AN:
33272
American (AMR)
AF:
0.00163
AC:
71
AN:
43580
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
24996
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39524
South Asian (SAS)
AF:
0.0000477
AC:
4
AN:
83786
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
52446
Middle Eastern (MID)
AF:
0.00193
AC:
11
AN:
5700
European-Non Finnish (NFE)
AF:
0.000128
AC:
141
AN:
1105522
Other (OTH)
AF:
0.00171
AC:
102
AN:
59816
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.470
Heterozygous variant carriers
0
52
104
155
207
259
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Exome Hom
Variant carriers
0
36
72
108
144
180
<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:
0.00706
AC:
1075
AN:
152218
Hom.:
15
Cov.:
32
AF XY:
0.00662
AC XY:
493
AN XY:
74430
show subpopulations
African (AFR)
AF:
0.0240
AC:
998
AN:
41524
American (AMR)
AF:
0.00333
AC:
51
AN:
15294
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3472
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5170
South Asian (SAS)
AF:
0.000207
AC:
1
AN:
4820
European-Finnish (FIN)
AF:
0.0000942
AC:
1
AN:
10614
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
294
European-Non Finnish (NFE)
AF:
0.000206
AC:
14
AN:
68006
Other (OTH)
AF:
0.00473
AC:
10
AN:
2112
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.504
Heterozygous variant carriers
0
50
100
151
201
251
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Genome Het
Genome Hom
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
Alfa
AF:
0.00312
Hom.:
1
Bravo
AF:
0.00784
Asia WGS
AF:
0.00231
AC:
8
AN:
3478

ClinVar

Significance: Benign/Likely benign
Submissions summary: Benign:10
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

not specified Benign:3
Aug 22, 2016
Athena Diagnostics
Significance:Benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Jun 21, 2013
GeneDx
Significance:Benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This variant is considered likely benign or benign based on one or more of the following criteria: it is a conservative change, it occurs at a poorly conserved position in the protein, it is predicted to be benign by multiple in silico algorithms, and/or has population frequency not consistent with disease. -

-
Genetic Services Laboratory, University of Chicago
Significance:Likely benign
Review Status:no assertion criteria provided
Collection Method:clinical testing

Likely benign based on allele frequency in 1000 Genomes Project or ESP global frequency and its presence in a patient with a rare or unrelated disease phenotype. NOT Sanger confirmed. -

Seizures, benign familial neonatal, 2 Benign:2
Apr 07, 2022
Fulgent Genetics, Fulgent Genetics
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Jan 12, 2018
Illumina Laboratory Services, Illumina
Significance:Benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score and internal cut-off values, a variant classified as benign is not then subjected to further curation. The score for this variant resulted in a classification of benign for this disease. -

Benign neonatal seizures Benign:2
Feb 02, 2025
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Jun 14, 2016
Illumina Laboratory Services, Illumina
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Inborn genetic diseases Benign:1
Apr 18, 2016
Ambry Genetics
Significance:Benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This alteration is classified as 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. -

KCNQ3-related disorder Benign:1
Apr 10, 2019
PreventionGenetics, part of Exact Sciences
Significance:Benign
Review Status:no assertion criteria provided
Collection Method:clinical testing

This variant is classified as benign based on ACMG/AMP sequence variant interpretation guidelines (Richards et al. 2015 PMID: 25741868, with internal and published modifications). -

not provided Benign:1
-
Breakthrough Genomics, Breakthrough Genomics
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:not provided

- -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
BayesDel_noAF
Benign
-0.71
CADD
Benign
2.8
DANN
Benign
0.72
PhyloP100
-2.1
Mutation Taster
=100/0
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: rs35538317; hg19: chr8-133152340; COSMIC: COSV66477124; API