rs794729197

Positions:

• chr20-63442523-G-GGGT

Variant summary

Our verdict is Likely pathogenic. Variant got 7 ACMG points: 7P and 0B. PM1 PM2 PM4_Supporting PP3 PP5

The NM_172107.4(KCNQ2):​c.698_699insACC​(p.Val233_Thr234insPro) variant causes a disruptive inframe insertion change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. Variant has been reported in ClinVar as Pathogenic (no stars).

• Frequency: Genomes: not found (cov: 29)
• Consequence: KCNQ2 NM_172107.4 disruptive_inframe_insertion
• Clinical Significance: Pathogenic no assertion criteria provided P:1
• Conservation: PhyloP100: 9.11

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]

KCNQ2 (HGNC:):

ACMG classification

Verdict is Likely_pathogenic. Variant got 7 ACMG points.

• PM1: In a region_of_interest Mediates interaction with SLC5A3 (size 101) in uniprot entity KCNQ2_HUMAN there are 33 pathogenic changes around while only 0 benign (100%) in NM_172107.4
• 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.
• PP3: No computational evidence supports a deleterious effect, but strongly conserved according to phyloP
• PP5: Variant 20-63442523-G-GGGT is Pathogenic according to our data. Variant chr20-63442523-G-GGGT is described in ClinVar as [Pathogenic]. Clinvar id is 202170.Status of the report is no_assertion_criteria_provided, 0 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
KCNQ2	NM_172107.4	c.698_699insACC	p.Val233_Thr234insPro	disruptive_inframe_insertion	5/17	ENST00000359125.7	NP_742105.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
KCNQ2	ENST00000359125.7	c.698_699insACC	p.Val233_Thr234insPro	disruptive_inframe_insertion	5/17	1	NM_172107.4	ENSP00000352035.2

Frequencies

GnomAD3 genomes Cov.: 29

GnomAD4 exome Cov.: 33

GnomAD4 genome Cov.: 29

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:1

Revision: no assertion criteria provided

Submissions by phenotype

Developmental and epileptic encephalopathy, 7 Pathogenic:1

Pathogenic, no assertion criteria provided

clinical testing

Mendelics

May 13, 2016

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Computational scores

Source: dbNSFP v4.3

Splicing

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

Publications

LitVar

Other links and lift over

dbSNP: rs794729197; hg19: chr20-62073876;