chr20-63419611-C-T

Variant summary

Our verdict is Benign. Variant got -12 ACMG points: 0P and 12B. BP4_ModerateBP6_ModerateBS1BS2

The NM_172107.4(KCNQ2):​c.1301+8G>A variant causes a splice region, intron change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000255 in 1,608,312 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 3/3 splice prediction tools predict no significant impact on normal splicing. Variant has been reported in ClinVar as Likely benign (★).

Frequency

Genomes: 𝑓 0.000013 ( 0 hom., cov: 33)
Exomes 𝑓: 0.000027 ( 0 hom. )

Consequence

KCNQ2
NM_172107.4 splice_region, intron

Scores

2
Splicing: ADA: 0.001107
2

Clinical Significance

Likely benign criteria provided, single submitter B:1

Conservation

PhyloP100: 0.641
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 -12 ACMG points.

BP4
Computational evidence support a benign effect (BayesDel_noAF=-0.26).
BP6
Variant 20-63419611-C-T is Benign according to our data. Variant chr20-63419611-C-T is described in ClinVar as [Likely_benign]. Clinvar id is 754523.Status of the report is criteria_provided_single_submitter, 1 stars.
BS1
Variant frequency is greater than expected in population sas. gnomad4_exome allele frequency = 0.0000268 (39/1455962) while in subpopulation SAS AF= 0.000189 (16/84832). AF 95% confidence interval is 0.000117. There are 0 homozygotes in gnomad4_exome. There are 24 alleles in male gnomad4_exome subpopulation. Median coverage is 31. This position pass quality control queck.
BS2
High AC in GnomAdExome4 at 39 AD gene.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect #exon/exons MANE Protein UniProt
KCNQ2NM_172107.4 linkuse as main transcriptc.1301+8G>A splice_region_variant, intron_variant ENST00000359125.7 NP_742105.1 O43526-1

Ensembl

Gene Transcript HGVSc HGVSp Effect #exon/exons TSL MANE Protein Appris UniProt
KCNQ2ENST00000359125.7 linkuse as main transcriptc.1301+8G>A splice_region_variant, intron_variant 1 NM_172107.4 ENSP00000352035.2 O43526-1

Frequencies

GnomAD3 genomes
AF:
0.0000131
AC:
2
AN:
152232
Hom.:
0
Cov.:
33
show subpopulations
Gnomad AFR
AF:
0.00
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.00
Gnomad ASJ
AF:
0.00
Gnomad EAS
AF:
0.00
Gnomad SAS
AF:
0.000414
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.00
Gnomad OTH
AF:
0.00
GnomAD3 exomes
AF:
0.0000209
AC:
5
AN:
239480
Hom.:
0
AF XY:
0.0000386
AC XY:
5
AN XY:
129620
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.00
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad SAS exome
AF:
0.000172
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.00
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000268
AC:
39
AN:
1455962
Hom.:
0
Cov.:
31
AF XY:
0.0000332
AC XY:
24
AN XY:
723698
show subpopulations
Gnomad4 AFR exome
AF:
0.00
Gnomad4 AMR exome
AF:
0.00
Gnomad4 ASJ exome
AF:
0.00
Gnomad4 EAS exome
AF:
0.00
Gnomad4 SAS exome
AF:
0.000189
Gnomad4 FIN exome
AF:
0.00
Gnomad4 NFE exome
AF:
0.0000189
Gnomad4 OTH exome
AF:
0.0000332
GnomAD4 genome
AF:
0.0000131
AC:
2
AN:
152350
Hom.:
0
Cov.:
33
AF XY:
0.0000268
AC XY:
2
AN XY:
74510
show subpopulations
Gnomad4 AFR
AF:
0.00
Gnomad4 AMR
AF:
0.00
Gnomad4 ASJ
AF:
0.00
Gnomad4 EAS
AF:
0.00
Gnomad4 SAS
AF:
0.000414
Gnomad4 FIN
AF:
0.00
Gnomad4 NFE
AF:
0.00
Gnomad4 OTH
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), LabcorpMar 14, 2018- -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
BayesDel_noAF
Benign
-0.26
CADD
Benign
14
DANN
Benign
0.94

Splicing

Name
Calibrated prediction
Score
Prediction
dbscSNV1_ADA
Benign
0.0011
dbscSNV1_RF
Benign
0.052
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

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

Other links and lift over

dbSNP: rs532111320; hg19: chr20-62050964; API