8-132174335-G-A

Position:

chr8-132174335-G-A

Variant summary

Our verdict is Benign. Variant got -19 ACMG points: 0P and 19B. BP4_ModerateBP6_Very_StrongBP7BS1BS2

The ENST00000388996.10(KCNQ3):c.948C>T(p.Thr316=) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000932 in 1,551,784 control chromosomes in the GnomAD database, including 15 homozygotes. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Likely benign (★★). Synonymous variant affecting the same amino acid position (i.e. T316T) has been classified as Likely benign.

Frequency

Genomes: 𝑓 0.0052 ( 11 hom., cov: 32)

Exomes 𝑓: 0.00047 ( 4 hom. )

Consequence

KCNQ3
ENST00000388996.10 synonymous

Scores

Clinical Significance

Benign/Likely benign criteria provided, multiple submitters, no conflicts B:7

Conservation

PhyloP100: 0.922

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 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Benign. Variant got -19 ACMG points.

BP4

Computational evidence support a benign effect (BayesDel_noAF=-0.36).

BP6

Variant 8-132174335-G-A is Benign according to our data. Variant chr8-132174335-G-A is described in ClinVar as [Likely_benign]. Clinvar id is 138040.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

BP7

Synonymous conserved (PhyloP=0.922 with no splicing effect.

BS1

Variant frequency is greater than expected in population afr. gnomad4 allele frequency = 0.00517 (788/152294) while in subpopulation AFR AF= 0.0181 (751/41558). AF 95% confidence interval is 0.017. There are 11 homozygotes in gnomad4. There are 391 alleles in male gnomad4 subpopulation. Median coverage is 32. This position pass quality control queck.

BS2

High AC in GnomAd4 at 788 AD gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
KCNQ3	NM_004519.4 linkuse as main transcript	c.948C>T	p.Thr316=	synonymous_variant	6/15	ENST00000388996.10	NP_004510.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
KCNQ3	ENST00000388996.10 linkuse as main transcript	c.948C>T	p.Thr316=	synonymous_variant	6/15	1	NM_004519.4	ENSP00000373648	P1	O43525-1

Frequencies

GnomAD3 genomes

AF:

0.00517

AC:

787

AN:

152176

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0181

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00177

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:

0.0000441

Gnomad OTH

AF:

0.00334

GnomAD3 exomes

AF:

0.00114

AC:

180

AN:

157422

Hom.:

AF XY:

0.000797

AC XY:

AN XY:

82780

show subpopulations

Gnomad AFR exome

AF:

0.0171

Gnomad AMR exome

AF:

0.00101

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:

0.0000327

Gnomad OTH exome

AF:

0.000451

GnomAD4 exome

AF:

0.000471

AC:

659

AN:

1399490

Hom.:

Cov.:

AF XY:

0.000380

AC XY:

262

AN XY:

690314

show subpopulations

Gnomad4 AFR exome

AF:

0.0172

Gnomad4 AMR exome

AF:

0.00103

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.0000126

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.0000139

Gnomad4 OTH exome

AF:

0.00105

GnomAD4 genome

AF:

0.00517

AC:

788

AN:

152294

Hom.:

Cov.:

AF XY:

0.00525

AC XY:

391

AN XY:

74470

show subpopulations

Gnomad4 AFR

AF:

0.0181

Gnomad4 AMR

AF:

0.00176

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.0000441

Gnomad4 OTH

AF:

0.00331

Alfa

AF:

0.00285

Hom.:

Bravo

AF:

0.00575

ClinVar

Significance: Benign/Likely benign

Submissions summary: Benign:7

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

not specified

Benign:2

Benign, criteria provided, single submitter	clinical testing	GeneDx	Apr 18, 2013	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. -
Likely benign, criteria provided, single submitter	clinical testing	Genetic Services Laboratory, University of Chicago	Aug 06, 2015	- -

Benign neonatal seizures

Benign:2

Benign, criteria provided, single submitter	clinical testing	Labcorp Genetics (formerly Invitae), Labcorp	Jan 30, 2024	- -
Likely benign, criteria provided, single submitter	clinical testing	Illumina Laboratory Services, Illumina	Jun 14, 2016	- -

Inborn genetic diseases

Benign:1

Benign, criteria provided, single submitter

clinical testing

Ambry Genetics

Jul 28, 2016

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. -

Seizures, benign familial neonatal, 2

Benign:1

Benign, criteria provided, single submitter

clinical testing

Illumina Laboratory Services, Illumina

Jan 13, 2018

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. -

not provided

Benign:1

Likely benign, criteria provided, single submitter

not provided

Breakthrough Genomics, Breakthrough Genomics

- -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

BayesDel_noAF

Benign

-0.36

CADD

Benign

9.4

DANN

Benign

0.74

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.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over