rs1057516118

Positions:

• chr20-63414927-C-G
• chr20-63414927-C-T

Variant summary

Our verdict is Uncertain significance. Variant got 4 ACMG points: 4P and 0B. PM2 PP2 PP3

The NM_172107.4(KCNQ2):​c.1501G>C​(p.Ala501Pro) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as not provided (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. A501V) has been classified as Uncertain significance.

• Frequency: Genomes: not found (cov: 32)
• Consequence: KCNQ2 NM_172107.4 missense
• Clinical Significance: not provided no classification provided O:1
• Conservation: PhyloP100: 2.19

Genes affected

KCNQ2 (HGNC:6296): (potassium voltage-gated channel subfamily Q member 2) The M channel is a slowly activating and deactivating potassium channel that plays a critical role in the regulation of neuronal excitability. The M channel is formed by the association of the protein encoded by this gene and a related protein encoded by the KCNQ3 gene, both integral membrane proteins. M channel currents are inhibited by M1 muscarinic acetylcholine receptors and activated by retigabine, a novel anti-convulsant drug. Defects in this gene are a cause of benign familial neonatal convulsions type 1 (BFNC), also known as epilepsy, benign neonatal type 1 (EBN1). At least five transcript variants encoding five different isoforms have been found for this gene. [provided by RefSeq, Jul 2008]

ACMG classification

Verdict is Uncertain_significance. Variant got 4 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP2: Missense variant where missense usually causes diseases, KCNQ2
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.758

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
KCNQ2	NM_172107.4	c.1501G>C	p.Ala501Pro	missense_variant	13/17	ENST00000359125.7

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
KCNQ2	ENST00000359125.7	c.1501G>C	p.Ala501Pro	missense_variant	13/17	1	NM_172107.4	A1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 35

GnomAD4 genome Cov.: 32

ClinVar

Significance: not provided

Submissions summary: Other:1

Revision: no classification provided

Submissions by phenotype

Developmental and epileptic encephalopathy, 7 Other:1

not provided, no classification provided

literature only

GeneReviews

-

EE (epileptic encephalopathy) -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.22
BayesDel_addAF	Pathogenic	0.28	D
BayesDel_noAF	Pathogenic	0.17
CADD	Benign	23
DANN	Uncertain	1.0
Eigen	Benign	0.17
Eigen_PC	Benign	0.14
FATHMM_MKL	Pathogenic	0.97	D
LIST_S2	Uncertain	0.94	D;D;D;D;D;D;D;D;D;D;D
M_CAP	Pathogenic	0.66	D
MetaRNN	Pathogenic	0.76	D;D;D;D;D;D;D;D;D;D;D
MetaSVM	Pathogenic	1.1	D
MutationTaster	Benign	1.0	D;D;D;D;D;D;D;D;D;D
PrimateAI	Uncertain	0.60	T
Sift4G	Benign	0.21	T;T;T;T;T;.;T;T;T;T;T
Polyphen		0.95	P;.;.;.;.;.;D;.;P;P;.
Vest4		0.60
MutPred		0.55		.;.;.;.;.;.;Gain of glycosylation at A501 (P = 0.0329);.;.;.;.;
MVP		0.90
MPC		1.7
ClinPred		0.81	D
GERP RS		5.2
Varity_R		0.58
gMVP		0.70

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

Other links and lift over

dbSNP: rs1057516118; hg19: chr20-62046280;