chr20-63424190-CCGG-C

Position:

• chr20-63424190-CCGG-C

Variant summary

Our verdict is Uncertain significance. Variant got 4 ACMG points: 4P and 0B. PM2 PM4_Supporting PP5

The NM_172107.4(KCNQ2):​c.1231_1233del​(p.Pro411del) variant causes a inframe deletion change. The variant was absent in control chromosomes in GnomAD project. Variant has been reported in ClinVar as Pathogenic (no stars). Synonymous variant affecting the same amino acid position (i.e. P411P) has been classified as Likely benign.

• Frequency: Genomes: not found (cov: 32)
• Consequence: KCNQ2 NM_172107.4 inframe_deletion
• Clinical Significance: Pathogenic no assertion criteria provided P:1
• Conservation: PhyloP100: 5.07

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]

(HGNC:):

ACMG classification

Verdict is Uncertain_significance. Variant got 4 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PM4: Nonframeshift variant in NON repetitive region in NM_172107.4. Strenght limited to Supporting due to length of the change: 1aa.
• PP5: Variant 20-63424190-CCGG-C is Pathogenic according to our data. Variant chr20-63424190-CCGG-C is described in ClinVar as [Pathogenic]. Clinvar id is 369790.Status of the report is no_assertion_criteria_provided, 0 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
KCNQ2	NM_172107.4	c.1231_1233del	p.Pro411del	inframe_deletion	11/17	ENST00000359125.7

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
KCNQ2	ENST00000359125.7	c.1231_1233del	p.Pro411del	inframe_deletion	11/17	1	NM_172107.4	A1
	ENST00000629794.1	n.362-204_362-202del		intron_variant, non_coding_transcript_variant		5

Frequencies

GnomAD3 genomes Cov.: 32

We have no GnomAD4 exomes data on this position. Probably position not covered by the project.

GnomAD4 genome Cov.: 32

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:1

Revision: no assertion criteria provided

Submissions by phenotype

Seizures, benign familial neonatal, 1 Pathogenic:1

Pathogenic, no assertion criteria provided

literature only

GeneReviews

Mar 31, 2016

BFNE (benign familial neonatal epilepsy) -

Computational scores

Source: dbNSFP v4.3

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.16		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: rs1060499544; hg19: chr20-62055543;