chr8-132129758-C-A

Variant summary

Our verdict is Benign. Variant got -7 ACMG points: 0P and 7B. BP4_ModerateBP6BS2

The NM_004519.4(KCNQ3):​c.2123G>T​(p.Ser708Ile) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000105 in 1,614,064 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 12/21 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

Frequency

Genomes: 𝑓 0.000013 ( 0 hom., cov: 32)
Exomes 𝑓: 0.000010 ( 0 hom. )

Consequence

KCNQ3
NM_004519.4 missense

Scores

8
11

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:3B:1

Conservation

PhyloP100: 1.58
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]

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Benign. Variant got -7 ACMG points.

BP4
Computational evidence support a benign effect (MetaRNN=0.22429222).
BP6
Variant 8-132129758-C-A is Benign according to our data. Variant chr8-132129758-C-A is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 413257.We mark this variant Likely_benign, oryginal submissions are: {Likely_benign=1, Uncertain_significance=2}.
BS2
High AC in GnomAdExome4 at 15 AD gene.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect #exon/exons MANE Protein UniProt
KCNQ3NM_004519.4 linkuse as main transcriptc.2123G>T p.Ser708Ile missense_variant 15/15 ENST00000388996.10 NP_004510.1 O43525-1

Ensembl

Gene Transcript HGVSc HGVSp Effect #exon/exons TSL MANE Protein Appris UniProt
KCNQ3ENST00000388996.10 linkuse as main transcriptc.2123G>T p.Ser708Ile missense_variant 15/151 NM_004519.4 ENSP00000373648.3 O43525-1

Frequencies

GnomAD3 genomes
AF:
0.0000131
AC:
2
AN:
152178
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.00
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.00
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
GnomAD3 exomes
AF:
0.00000398
AC:
1
AN:
251376
Hom.:
0
AF XY:
0.00
AC XY:
0
AN XY:
135882
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.00
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad SAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.00000880
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000103
AC:
15
AN:
1461886
Hom.:
0
Cov.:
32
AF XY:
0.0000110
AC XY:
8
AN XY:
727246
show subpopulations
Gnomad4 AFR exome
AF:
0.00
Gnomad4 AMR exome
AF:
0.00
Gnomad4 ASJ exome
AF:
0.00
Gnomad4 EAS exome
AF:
0.00
Gnomad4 SAS exome
AF:
0.00
Gnomad4 FIN exome
AF:
0.00
Gnomad4 NFE exome
AF:
0.0000135
Gnomad4 OTH exome
AF:
0.00
GnomAD4 genome
AF:
0.0000131
AC:
2
AN:
152178
Hom.:
0
Cov.:
32
AF XY:
0.00
AC XY:
0
AN XY:
74354
show subpopulations
Gnomad4 AFR
AF:
0.00
Gnomad4 AMR
AF:
0.00
Gnomad4 ASJ
AF:
0.00
Gnomad4 EAS
AF:
0.00
Gnomad4 SAS
AF:
0.00
Gnomad4 FIN
AF:
0.00
Gnomad4 NFE
AF:
0.0000294
Gnomad4 OTH
AF:
0.00
Alfa
AF:
0.0000354
Hom.:
0
Bravo
AF:
0.0000151
EpiCase
AF:
0.000164
EpiControl
AF:
0.00

ClinVar

Significance: Conflicting classifications of pathogenicity
Submissions summary: Uncertain:3Benign:1
Revision: criteria provided, conflicting classifications
LINK: link

Submissions by phenotype

not provided Uncertain:3
Uncertain significance, criteria provided, single submitterclinical testingGeneDxFeb 05, 2020Not observed at a significant frequency in large population cohorts (Lek et al., 2016); In silico analysis supports that this missense variant does not alter protein structure/function; Has not been previously published as pathogenic or benign to our knowledge -
Uncertain significance, no assertion criteria providedclinical testingDepartment of Pathology and Laboratory Medicine, Sinai Health System-The KCNQ3 p.Ser588Ile variant was not identified in the literature nor was it identified in LOVD 3.0. The variant was identified in dbSNP (ID: rs977989588) and in ClinVar (classified as likely benign by Invitae and as uncertain significance by CeGaT (Germany)). The variant was identified in control databases in 2 of 282774 chromosomes at a frequency of 0.000007073 (Genome Aggregation Database March 6, 2019, v2.1.1). The variant was observed in the European (non-Finnish) population in 2 of 129126 chromosomes (freq: 0.000015), but was not observed in the African, Latino, Ashkenazi Jewish, East Asian, European (Finnish), Other, or South Asian populations. The p.Ser588 residue is not conserved in mammals and computational analyses (PolyPhen-2, SIFT, AlignGVGD, BLOSUM, MutationTaster) do not suggest a high likelihood of impact to the protein; however, this information is not predictive enough to rule out pathogenicity. The variant occurs outside of the splicing consensus sequence and 3 of 4 in silico or computational prediction software programs (SpliceSiteFinder, MaxEntScan, NNSPLICE, GeneSplicer) do not predict a difference in splicing. In summary, based on the above information the clinical significance of this variant cannot be determined with certainty at this time. This variant is classified as a variant of uncertain significance. -
Uncertain significance, criteria provided, single submitterclinical testingCeGaT Center for Human Genetics TuebingenJan 01, 2018- -
Benign neonatal seizures Benign:1
Likely benign, criteria provided, single submitterclinical testingLabcorp Genetics (formerly Invitae), LabcorpApr 28, 2023- -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.098
BayesDel_addAF
Uncertain
0.069
D
BayesDel_noAF
Benign
-0.14
CADD
Benign
21
DANN
Uncertain
0.98
DEOGEN2
Uncertain
0.55
D;.;.;.;.
Eigen
Benign
-0.31
Eigen_PC
Benign
-0.12
FATHMM_MKL
Uncertain
0.91
D
LIST_S2
Benign
0.84
T;T;T;T;T
M_CAP
Uncertain
0.087
D
MetaRNN
Benign
0.22
T;T;T;T;T
MetaSVM
Uncertain
0.44
D
MutationAssessor
Benign
0.55
N;.;.;.;.
PrimateAI
Benign
0.36
T
PROVEAN
Benign
-2.2
N;.;N;N;.
REVEL
Uncertain
0.39
Sift
Benign
0.098
T;.;T;T;.
Sift4G
Uncertain
0.016
D;D;D;D;.
Polyphen
0.070
B;.;.;B;.
Vest4
0.14
MVP
0.47
MPC
0.16
ClinPred
0.093
T
GERP RS
5.6
Varity_R
0.17
gMVP
0.38

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

LitVar

Below is the list of publications found by LitVar. It may be empty.

Other links and lift over

dbSNP: rs977989588; hg19: chr8-133142005; COSMIC: COSV66482772; API