chr20-63445350-G-A

Variant summary

Our verdict is Benign. Variant got -15 ACMG points: 0P and 15B. BP4_StrongBP6_ModerateBP7BS1BS2

The NM_172107.4(KCNQ2):​c.402C>T​(p.Ile134=) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000279 in 1,613,694 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Likely benign (★).

Frequency

Genomes: 𝑓 0.00013 ( 0 hom., cov: 34)
Exomes 𝑓: 0.000017 ( 0 hom. )

Consequence

KCNQ2
NM_172107.4 synonymous

Scores

2

Clinical Significance

Likely benign criteria provided, single submitter B:1

Conservation

PhyloP100: 0.285
Variant links:
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]

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ACMG classification

Classification made for transcript

Verdict is Benign. Variant got -15 ACMG points.

BP4
Computational evidence support a benign effect (BayesDel_noAF=-0.48).
BP6
Variant 20-63445350-G-A is Benign according to our data. Variant chr20-63445350-G-A is described in ClinVar as [Likely_benign]. Clinvar id is 413253.Status of the report is criteria_provided_single_submitter, 1 stars.
BP7
Synonymous conserved (PhyloP=0.285 with no splicing effect.
BS1
Variant frequency is greater than expected in population afr. gnomad4 allele frequency = 0.000131 (20/152350) while in subpopulation AFR AF= 0.000433 (18/41576). AF 95% confidence interval is 0.000279. There are 0 homozygotes in gnomad4. There are 12 alleles in male gnomad4 subpopulation. Median coverage is 34. This position pass quality control queck.
BS2
High AC in GnomAd4 at 20 AD gene.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect #exon/exons MANE Protein UniProt
KCNQ2NM_172107.4 linkuse as main transcriptc.402C>T p.Ile134= synonymous_variant 3/17 ENST00000359125.7 NP_742105.1

Ensembl

Gene Transcript HGVSc HGVSp Effect #exon/exons TSL MANE Protein Appris UniProt
KCNQ2ENST00000359125.7 linkuse as main transcriptc.402C>T p.Ile134= synonymous_variant 3/171 NM_172107.4 ENSP00000352035 A1O43526-1

Frequencies

GnomAD3 genomes
AF:
0.000131
AC:
20
AN:
152232
Hom.:
0
Cov.:
34
show subpopulations
Gnomad AFR
AF:
0.000434
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.0000654
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
GnomAD3 exomes
AF:
0.0000359
AC:
9
AN:
250632
Hom.:
0
AF XY:
0.0000442
AC XY:
6
AN XY:
135734
show subpopulations
Gnomad AFR exome
AF:
0.000247
Gnomad AMR exome
AF:
0.0000868
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:
0.0000177
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000171
AC:
25
AN:
1461344
Hom.:
0
Cov.:
32
AF XY:
0.0000179
AC XY:
13
AN XY:
726954
show subpopulations
Gnomad4 AFR exome
AF:
0.000299
Gnomad4 AMR exome
AF:
0.0000447
Gnomad4 ASJ exome
AF:
0.00
Gnomad4 EAS exome
AF:
0.00
Gnomad4 SAS exome
AF:
0.0000116
Gnomad4 FIN exome
AF:
0.00
Gnomad4 NFE exome
AF:
0.00000899
Gnomad4 OTH exome
AF:
0.0000331
GnomAD4 genome
AF:
0.000131
AC:
20
AN:
152350
Hom.:
0
Cov.:
34
AF XY:
0.000161
AC XY:
12
AN XY:
74500
show subpopulations
Gnomad4 AFR
AF:
0.000433
Gnomad4 AMR
AF:
0.0000653
Gnomad4 ASJ
AF:
0.00
Gnomad4 EAS
AF:
0.00
Gnomad4 SAS
AF:
0.00
Gnomad4 FIN
AF:
0.00
Gnomad4 NFE
AF:
0.0000147
Gnomad4 OTH
AF:
0.00
Alfa
AF:
0.0000329
Hom.:
0
Bravo
AF:
0.000102
EpiCase
AF:
0.0000545
EpiControl
AF:
0.00

ClinVar

Significance: Likely benign
Submissions summary: Benign:1
Revision: criteria provided, single submitter
LINK: link

Submissions by phenotype

Early infantile epileptic encephalopathy with suppression bursts Benign:1
Likely benign, criteria provided, single submitterclinical testingLabcorp Genetics (formerly Invitae), LabcorpDec 27, 2023- -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
BayesDel_noAF
Benign
-0.48
CADD
Benign
9.0
DANN
Benign
0.77

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

Publications

LitVar

Below is the list of publications found by LitVar. It may be empty.

Other links and lift over

dbSNP: rs140712277; hg19: chr20-62076703; COSMIC: COSV100609195; COSMIC: COSV100609195; API