rs772971971

Variant summary

Our verdict is Benign. Variant got -8 ACMG points: 0P and 8B. BP4_StrongBS2

The NM_172107.4(KCNQ2):​c.1888-3C>T variant causes a splice region, splice polypyrimidine tract, intron change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000288 in 1,597,662 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 2/2 splice prediction tools predict no significant impact on normal splicing. Variant has been reported in ClinVar as Uncertain significance (★★).

Frequency

Genomes: 𝑓 0.000039 ( 0 hom., cov: 33)
Exomes 𝑓: 0.000028 ( 0 hom. )

Consequence

KCNQ2
NM_172107.4 splice_region, splice_polypyrimidine_tract, intron

Scores

2
Splicing: ADA: 0.3551
1

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:3

Conservation

PhyloP100: 0.766
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]

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Benign. Variant got -8 ACMG points.

BP4
Computational evidence support a benign effect (BayesDel_noAF=-0.79).
BS2
High AC in GnomAd4 at 6 AD gene.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect #exon/exons MANE Protein UniProt
KCNQ2NM_172107.4 linkuse as main transcriptc.1888-3C>T splice_region_variant, splice_polypyrimidine_tract_variant, intron_variant ENST00000359125.7 NP_742105.1

Ensembl

Gene Transcript HGVSc HGVSp Effect #exon/exons TSL MANE Protein Appris UniProt
KCNQ2ENST00000359125.7 linkuse as main transcriptc.1888-3C>T splice_region_variant, splice_polypyrimidine_tract_variant, intron_variant 1 NM_172107.4 ENSP00000352035 A1O43526-1

Frequencies

GnomAD3 genomes
AF:
0.0000394
AC:
6
AN:
152254
Hom.:
0
Cov.:
33
show subpopulations
Gnomad AFR
AF:
0.0000482
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.00
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:
0.0000588
Gnomad OTH
AF:
0.00
GnomAD3 exomes
AF:
0.0000213
AC:
5
AN:
234416
Hom.:
0
AF XY:
0.0000233
AC XY:
3
AN XY:
128804
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:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.0000458
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000277
AC:
40
AN:
1445408
Hom.:
0
Cov.:
36
AF XY:
0.0000278
AC XY:
20
AN XY:
719296
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:
0.0000116
Gnomad4 FIN exome
AF:
0.00
Gnomad4 NFE exome
AF:
0.0000342
Gnomad4 OTH exome
AF:
0.0000166
GnomAD4 genome
AF:
0.0000394
AC:
6
AN:
152254
Hom.:
0
Cov.:
33
AF XY:
0.0000269
AC XY:
2
AN XY:
74388
show subpopulations
Gnomad4 AFR
AF:
0.0000482
Gnomad4 AMR
AF:
0.00
Gnomad4 ASJ
AF:
0.00
Gnomad4 EAS
AF:
0.00
Gnomad4 SAS
AF:
0.00
Gnomad4 FIN
AF:
0.00
Gnomad4 NFE
AF:
0.0000588
Gnomad4 OTH
AF:
0.00
Bravo
AF:
0.0000264
EpiCase
AF:
0.0000545
EpiControl
AF:
0.00

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:3
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Early infantile epileptic encephalopathy with suppression bursts Uncertain:1
Uncertain significance, criteria provided, single submitterclinical testingLabcorp Genetics (formerly Invitae), LabcorpDec 27, 2022In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. Variants that disrupt the consensus splice site are a relatively common cause of aberrant splicing (PMID: 17576681, 9536098). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant is not likely to affect RNA splicing. ClinVar contains an entry for this variant (Variation ID: 283738). This variant has not been reported in the literature in individuals affected with KCNQ2-related conditions. This variant is present in population databases (rs772971971, gnomAD 0.006%). This sequence change falls in intron 16 of the KCNQ2 gene. It does not directly change the encoded amino acid sequence of the KCNQ2 protein. It affects a nucleotide within the consensus splice site. -
not provided Uncertain:1
Uncertain significance, criteria provided, single submitterclinical testingEurofins Ntd Llc (ga)Oct 12, 2015- -
Seizures, benign familial neonatal, 1;C3150986:Developmental and epileptic encephalopathy, 7 Uncertain:1
Uncertain significance, criteria provided, single submitterclinical testingFulgent Genetics, Fulgent GeneticsOct 31, 2018- -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
BayesDel_noAF
Benign
-0.79
CADD
Benign
11
DANN
Benign
0.57

Splicing

Name
Calibrated prediction
Score
Prediction
dbscSNV1_ADA
Benign
0.36
SpliceAI score (max)
0.060
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: rs772971971; hg19: chr20-62038731; API