rs147173555

Variant summary

Our verdict is Benign. The variant received -9 ACMG points: 0P and 9B. BP4_StrongBP6BS1

The NM_004519.4(KCNQ3):​c.1994C>T​(p.Ser665Leu) variant causes a missense change. The variant allele was found at a frequency of 0.000286 in 1,614,088 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 13/22 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Synonymous variant affecting the same amino acid position (i.e. S665S) has been classified as Likely benign.

Frequency

Genomes: 𝑓 0.0015 ( 0 hom., cov: 32)
Exomes 𝑓: 0.00016 ( 0 hom. )

Consequence

KCNQ3
NM_004519.4 missense

Scores

6
13

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:2B:5

Conservation

PhyloP100: 3.64

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: Benign. The variant received -9 ACMG points.

BP4
Computational evidence support a benign effect (MetaRNN=0.015188515).
BP6
Variant 8-132129887-G-A is Benign according to our data. Variant chr8-132129887-G-A is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 194513.
BS1
Variant frequency is greater than expected in population afr. GnomAd4 allele frequency = 0.00148 (226/152198) while in subpopulation AFR AF = 0.00506 (210/41532). AF 95% confidence interval is 0.0045. There are 0 homozygotes in GnomAd4. There are 95 alleles in the male GnomAd4 subpopulation. Median coverage is 32. This position passed quality control check.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
KCNQ3NM_004519.4 linkc.1994C>T p.Ser665Leu missense_variant Exon 15 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.1994C>T p.Ser665Leu missense_variant Exon 15 of 15 1 NM_004519.4 ENSP00000373648.3 O43525-1

Frequencies

GnomAD3 genomes
AF:
0.00147
AC:
224
AN:
152080
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.00502
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.000721
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:
0.00144
GnomAD2 exomes
AF:
0.000346
AC:
87
AN:
251486
AF XY:
0.000250
show subpopulations
Gnomad AFR exome
AF:
0.00455
Gnomad AMR exome
AF:
0.000202
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:
0.000326
GnomAD4 exome
AF:
0.000161
AC:
235
AN:
1461890
Hom.:
0
Cov.:
32
AF XY:
0.000155
AC XY:
113
AN XY:
727248
show subpopulations
African (AFR)
AF:
0.00469
AC:
157
AN:
33480
American (AMR)
AF:
0.000358
AC:
16
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:
0.0000580
AC:
5
AN:
86258
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53418
Middle Eastern (MID)
AF:
0.000173
AC:
1
AN:
5768
European-Non Finnish (NFE)
AF:
0.0000279
AC:
31
AN:
1112010
Other (OTH)
AF:
0.000414
AC:
25
AN:
60396
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.469
Heterozygous variant carriers
0
19
37
56
74
93
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
10
20
30
40
50
<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:
0.00148
AC:
226
AN:
152198
Hom.:
0
Cov.:
32
AF XY:
0.00128
AC XY:
95
AN XY:
74404
show subpopulations
African (AFR)
AF:
0.00506
AC:
210
AN:
41532
American (AMR)
AF:
0.000720
AC:
11
AN:
15280
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3468
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5162
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4824
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10610
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
294
European-Non Finnish (NFE)
AF:
0.0000294
AC:
2
AN:
68004
Other (OTH)
AF:
0.00142
AC:
3
AN:
2112
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.499
Heterozygous variant carriers
0
11
22
32
43
54
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Genome Het
Variant carriers
0
4
8
12
16
20
<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:
0.000691
Hom.:
0
Bravo
AF:
0.00156
ESP6500AA
AF:
0.00613
AC:
27
ESP6500EA
AF:
0.00
AC:
0
ExAC
AF:
0.000486
AC:
59
EpiCase
AF:
0.0000545
EpiControl
AF:
0.0000593

ClinVar

Significance: Conflicting classifications of pathogenicity
Submissions summary: Uncertain:2Benign:5
Revision: criteria provided, conflicting classifications
LINK: link

Submissions by phenotype

not provided Uncertain:1Benign:2
Feb 01, 2024
CeGaT Center for Human Genetics Tuebingen
Significance:Benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

KCNQ3: BS1, BS2 -

Mar 22, 2019
GeneDx
Significance:Benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Jun 25, 2015
Eurofins Ntd Llc (ga)
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Seizures, benign familial neonatal, 2 Uncertain:1Benign:1
May 23, 2017
Fulgent Genetics, Fulgent Genetics
Significance:Uncertain significance
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. -

Inborn genetic diseases Benign:1
Dec 15, 2017
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 27, 2025
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.063
BayesDel_addAF
Benign
-0.25
T
BayesDel_noAF
Benign
-0.13
CADD
Benign
20
DANN
Uncertain
0.99
DEOGEN2
Uncertain
0.55
D;.;.;.;.
Eigen
Benign
-0.41
Eigen_PC
Benign
-0.26
FATHMM_MKL
Uncertain
0.85
D
LIST_S2
Benign
0.79
T;T;T;T;T
M_CAP
Uncertain
0.28
D
MetaRNN
Benign
0.015
T;T;T;T;T
MetaSVM
Uncertain
0.34
D
MutationAssessor
Benign
1.2
L;.;.;.;.
PhyloP100
3.6
PrimateAI
Benign
0.32
T
PROVEAN
Benign
-2.2
N;.;N;N;.
REVEL
Uncertain
0.40
Sift
Benign
0.064
T;.;D;T;.
Sift4G
Benign
0.37
T;T;T;T;.
Polyphen
0.20
B;.;.;B;.
Vest4
0.11
MVP
0.49
MPC
0.093
ClinPred
0.020
T
GERP RS
3.8
Varity_R
0.11
gMVP
0.35
Mutation Taster
=83/17
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: rs147173555; hg19: chr8-133142134; COSMIC: COSV66481626; API