chr20-63414970-G-A

Variant summary

Our verdict is Benign. Variant got -19 ACMG points: 0P and 19B. BP4_ModerateBP6_Very_StrongBP7BS1BS2

The NM_172107.4(KCNQ2):​c.1458C>T​(p.Phe486Phe) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00068 in 1,612,130 control chromosomes in the GnomAD database, including 20 homozygotes. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Benign (★★).

Frequency

Genomes: 𝑓 0.00033 ( 0 hom., cov: 32)
Exomes 𝑓: 0.00072 ( 20 hom. )

Consequence

KCNQ2
NM_172107.4 synonymous

Scores

2

Clinical Significance

Benign criteria provided, multiple submitters, no conflicts B:4

Conservation

PhyloP100: -0.320
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 -19 ACMG points.

BP4
Computational evidence support a benign effect (BayesDel_noAF=-0.42).
BP6
Variant 20-63414970-G-A is Benign according to our data. Variant chr20-63414970-G-A is described in ClinVar as [Benign]. Clinvar id is 138024.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
BP7
Synonymous conserved (PhyloP=-0.32 with no splicing effect.
BS1
Variant frequency is greater than expected in population sas. gnomad4 allele frequency = 0.000329 (50/152128) while in subpopulation SAS AF= 0.0073 (35/4794). AF 95% confidence interval is 0.0054. There are 0 homozygotes in gnomad4. There are 32 alleles in male gnomad4 subpopulation. Median coverage is 32. This position pass quality control queck.
BS2
High AC in GnomAd4 at 50 AD gene.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
KCNQ2NM_172107.4 linkc.1458C>T p.Phe486Phe synonymous_variant Exon 13 of 17 ENST00000359125.7 NP_742105.1 O43526-1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
KCNQ2ENST00000359125.7 linkc.1458C>T p.Phe486Phe synonymous_variant Exon 13 of 17 1 NM_172107.4 ENSP00000352035.2 O43526-1

Frequencies

GnomAD3 genomes
AF:
0.000329
AC:
50
AN:
152010
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.0000483
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.0000655
Gnomad ASJ
AF:
0.00
Gnomad EAS
AF:
0.00
Gnomad SAS
AF:
0.00729
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.000176
Gnomad OTH
AF:
0.00
GnomAD3 exomes
AF:
0.00154
AC:
381
AN:
247104
Hom.:
11
AF XY:
0.00197
AC XY:
264
AN XY:
134276
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.0000579
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.0000545
Gnomad SAS exome
AF:
0.0117
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.000145
Gnomad OTH exome
AF:
0.000658
GnomAD4 exome
AF:
0.000716
AC:
1046
AN:
1460002
Hom.:
20
Cov.:
35
AF XY:
0.000991
AC XY:
720
AN XY:
726396
show subpopulations
Gnomad4 AFR exome
AF:
0.00
Gnomad4 AMR exome
AF:
0.0000671
Gnomad4 ASJ exome
AF:
0.0000383
Gnomad4 EAS exome
AF:
0.0000504
Gnomad4 SAS exome
AF:
0.0102
Gnomad4 FIN exome
AF:
0.00
Gnomad4 NFE exome
AF:
0.000101
Gnomad4 OTH exome
AF:
0.000779
GnomAD4 genome
AF:
0.000329
AC:
50
AN:
152128
Hom.:
0
Cov.:
32
AF XY:
0.000430
AC XY:
32
AN XY:
74356
show subpopulations
Gnomad4 AFR
AF:
0.0000481
Gnomad4 AMR
AF:
0.0000654
Gnomad4 ASJ
AF:
0.00
Gnomad4 EAS
AF:
0.00
Gnomad4 SAS
AF:
0.00730
Gnomad4 FIN
AF:
0.00
Gnomad4 NFE
AF:
0.000176
Gnomad4 OTH
AF:
0.00
Alfa
AF:
0.000346
Hom.:
0
Bravo
AF:
0.000178
Asia WGS
AF:
0.00491
AC:
17
AN:
3478
EpiCase
AF:
0.000164
EpiControl
AF:
0.000356

ClinVar

Significance: Benign
Submissions summary: Benign:4
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

not specified Benign:1
Feb 07, 2013
GeneDx
Significance: Benign
Review Status: criteria provided, single submitter
Collection Method: clinical testing

This variant is considered likely benign or benign based on one or more of the following criteria: it is a conservative change, it occurs at a poorly conserved position in the protein, it is predicted to be benign by multiple in silico algorithms, and/or has population frequency not consistent with disease. -

Inborn genetic diseases Benign:1
Oct 31, 2016
Ambry Genetics
Significance: Benign
Review Status: criteria provided, single submitter
Collection Method: clinical testing

This alteration is classified as benign based on a combination of the following: seen in unaffected individuals, population frequency, intact protein function, lack of segregation with disease, co-occurrence, RNA analysis, in silico models, amino acid conservation, lack of disease association in case-control studies, and/or the mechanism of disease or impacted region is inconsistent with a known cause of pathogenicity. -

Early infantile epileptic encephalopathy with suppression bursts Benign:1
Jan 06, 2025
Labcorp Genetics (formerly Invitae), Labcorp
Significance: Benign
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

not provided Benign:1
Aug 01, 2024
CeGaT Center for Human Genetics Tuebingen
Significance: Benign
Review Status: criteria provided, single submitter
Collection Method: clinical testing

KCNQ2: BP4, BP7, BS1, BS2 -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
BayesDel_noAF
Benign
-0.42
CADD
Benign
8.0
DANN
Benign
0.82

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: rs141951341; hg19: chr20-62046323; API