8-132132254-A-C

Variant names:

• chr8-132132254-A-C
• rs1060500606
• NM_004519.4:c.1810T>G

Variant summary

Our verdict is Uncertain significance. The variant received 2 ACMG points: 2P and 0B. PM2

The NM_004519.4(KCNQ3):​c.1810T>G​(p.Tyr604Asp) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000657 in 152,194 control chromosomes in the GnomAD database, with no homozygous occurrence. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. Y604C) has been classified as Uncertain significance.

• Frequency: Genomes: 𝑓 0.0000066 (0 hom., cov: 33)
• Consequence: KCNQ3 NM_004519.4 missense
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 8.37
• Publications: 1 publications found

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

ACMG classification

Our verdict: Uncertain_significance. The variant received 2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_004519.4. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	KCNQ3	NM_004519.4	MANE Select	c.1810T>G	p.Tyr604Asp	missense	Exon 14 of 15	NP_004510.1
	KCNQ3	NM_001204824.2		c.1450T>G	p.Tyr484Asp	missense	Exon 14 of 15	NP_001191753.1

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	KCNQ3	ENST00000388996.10	TSL:1 MANE Select	c.1810T>G	p.Tyr604Asp	missense	Exon 14 of 15	ENSP00000373648.3
	KCNQ3	ENST00000519445.5	TSL:5	c.1774T>G	p.Tyr592Asp	missense	Exon 14 of 15	ENSP00000428790.1
	KCNQ3	ENST00000521134.6	TSL:2	c.1450T>G	p.Tyr484Asp	missense	Exon 14 of 15	ENSP00000429799.1

Frequencies

GnomAD3 genomes AF: 0.00000657 AC: 1 AN: 152194 Hom.: 0 Cov.: 33

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: 0.0000147

Gnomad OTH AF: 0.00

GnomAD4 exome Cov.: 30

GnomAD4 genome AF: 0.00000657 AC: 1 AN: 152194 Hom.: 0 Cov.: 33 AF XY: 0.0000135 AC XY: 1 AN XY: 74346

African (AFR) AF: 0.00 AC: 0 AN: 41446

American (AMR) AF: 0.00 AC: 0 AN: 15278

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3472

East Asian (EAS) AF: 0.00 AC: 0 AN: 5192

South Asian (SAS) AF: 0.00 AC: 0 AN: 4830

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10614

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 316

European-Non Finnish (NFE) AF: 0.0000147 AC: 1 AN: 68042

Other (OTH) AF: 0.00 AC: 0 AN: 2094

Alfa AF: 0.00 Hom.: 0

Bravo AF: 0.00000378

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.25
BayesDel_addAF	Pathogenic	0.34	D
BayesDel_noAF	Pathogenic	0.25
CADD	Uncertain	24
DANN	Uncertain	0.99
DEOGEN2	Uncertain	0.73	D
Eigen	Uncertain	0.35
Eigen_PC	Uncertain	0.41
FATHMM_MKL	Pathogenic	1.0	D
LIST_S2	Benign	0.76	T
M_CAP	Pathogenic	0.35	D
MetaRNN	Uncertain	0.66	D
MetaSVM	Pathogenic	1.0	D
MutationAssessor	Uncertain	2.3	M
PhyloP100		8.4
PrimateAI	Uncertain	0.52	T
PROVEAN	Benign	-0.50	N
REVEL	Uncertain	0.57
Sift	Benign	0.10	T
Sift4G	Benign	0.13	T
Polyphen		0.99	D
Vest4		0.57
MutPred		0.34		Loss of phosphorylation at Y604 (P = 0.0228)
MVP		0.71
MPC		0.63
ClinPred		0.89	D
GERP RS		5.7
Varity_R		0.17
gMVP		0.61
Mutation Taster		=50/50

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.010		Details are displayed if max score is > 0.2

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

Other links and lift over

dbSNP: rs1060500606; hg19: chr8-133144501;