rs200872349

Variant summary

Our verdict is Benign. The variant received -10 ACMG points: 0P and 10B. BP4BP6BS1BS2

The NM_172107.4(KCNQ2):​c.1301+5C>T variant causes a splice region, intron change. The variant allele was found at a frequency of 0.0000236 in 1,609,060 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 Conflicting classifications of pathogenicity (no stars).

Frequency

Genomes: 𝑓 0.000046 ( 0 hom., cov: 33)
Exomes 𝑓: 0.000021 ( 0 hom. )

Consequence

KCNQ2
NM_172107.4 splice_region, intron

Scores

1
1
Splicing: ADA: 0.3421
2

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:2B:1

Conservation

PhyloP100: 4.88

Publications

0 publications found
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]
KCNQ2 Gene-Disease associations (from GenCC):
  • complex neurodevelopmental disorder
    Inheritance: AD Classification: DEFINITIVE Submitted by: ClinGen
  • developmental and epileptic encephalopathy, 7
    Inheritance: AD Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Orphanet, Labcorp Genetics (formerly Invitae), G2P
  • neonatal encephalopathy with non-epileptic myoclonus
    Inheritance: AD Classification: DEFINITIVE Submitted by: ClinGen
  • neonatal-onset developmental and epileptic encephalopathy
    Inheritance: AD Classification: DEFINITIVE Submitted by: ClinGen
  • seizures, benign familial neonatal, 1
    Inheritance: AD Classification: DEFINITIVE Submitted by: G2P
  • seizures, benign familial neonatal, 2
    Inheritance: AD Classification: STRONG Submitted by: Labcorp Genetics (formerly Invitae)
  • benign familial infantile epilepsy
    Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
  • benign familial neonatal-infantile seizures
    Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
  • benign neonatal seizures
    Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
  • malignant migrating partial seizures of infancy
    Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Benign. The variant received -10 ACMG points.

BP4
Computational evidence support a benign effect (BayesDel_noAF=-0.15).
BP6
Variant 20-63419614-G-A is Benign according to our data. Variant chr20-63419614-G-A is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 205904.
BS1
Variant frequency is greater than expected in population eas. GnomAdExome4 allele frequency = 0.0000213 (31/1456694) while in subpopulation EAS AF = 0.000203 (8/39498). AF 95% confidence interval is 0.000101. There are 0 homozygotes in GnomAdExome4. There are 19 alleles in the male GnomAdExome4 subpopulation. Median coverage is 31. This position passed quality control check.
BS2
High AC in GnomAd4 at 7 AD gene.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
KCNQ2NM_172107.4 linkc.1301+5C>T splice_region_variant, intron_variant Intron 12 of 16 ENST00000359125.7 NP_742105.1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
KCNQ2ENST00000359125.7 linkc.1301+5C>T splice_region_variant, intron_variant Intron 12 of 16 1 NM_172107.4 ENSP00000352035.2

Frequencies

GnomAD3 genomes
AF:
0.0000460
AC:
7
AN:
152248
Hom.:
0
Cov.:
33
show subpopulations
Gnomad AFR
AF:
0.0000241
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.0000654
Gnomad ASJ
AF:
0.00
Gnomad EAS
AF:
0.000385
Gnomad SAS
AF:
0.00
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.0000441
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.0000498
AC:
12
AN:
240736
AF XY:
0.0000767
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.0000593
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.000506
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.00000919
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000213
AC:
31
AN:
1456694
Hom.:
0
Cov.:
31
AF XY:
0.0000262
AC XY:
19
AN XY:
724156
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33464
American (AMR)
AF:
0.0000679
AC:
3
AN:
44194
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
25980
East Asian (EAS)
AF:
0.000203
AC:
8
AN:
39498
South Asian (SAS)
AF:
0.0000118
AC:
1
AN:
84990
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
52114
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5576
European-Non Finnish (NFE)
AF:
0.0000153
AC:
17
AN:
1110674
Other (OTH)
AF:
0.0000332
AC:
2
AN:
60204
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.488
Heterozygous variant carriers
0
1
3
4
6
7
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
2
4
6
8
10
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
GnomAD4 genome
AF:
0.0000459
AC:
7
AN:
152366
Hom.:
0
Cov.:
33
AF XY:
0.0000537
AC XY:
4
AN XY:
74510
show subpopulations
African (AFR)
AF:
0.0000240
AC:
1
AN:
41596
American (AMR)
AF:
0.0000653
AC:
1
AN:
15310
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3468
East Asian (EAS)
AF:
0.000386
AC:
2
AN:
5180
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4834
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10624
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
294
European-Non Finnish (NFE)
AF:
0.0000441
AC:
3
AN:
68036
Other (OTH)
AF:
0.00
AC:
0
AN:
2112
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.468
Heterozygous variant carriers
0
1
1
2
2
3
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Genome Het
Variant carriers
0
2
4
6
8
10
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
Alfa
AF:
0.0000329
Hom.:
0
Bravo
AF:
0.0000453
Asia WGS
AF:
0.000577
AC:
2
AN:
3478

ClinVar

Significance: Conflicting classifications of pathogenicity
Submissions summary: Uncertain:2Benign:1
Revision: criteria provided, conflicting classifications
LINK: link

Submissions by phenotype

Developmental and epileptic encephalopathy Uncertain:1
Apr 24, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change falls in intron 12 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. This variant is present in population databases (rs200872349, gnomAD 0.05%). This variant has not been reported in the literature in individuals affected with KCNQ2-related conditions. ClinVar contains an entry for this variant (Variation ID: 205904). 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. In 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. -

See cases Uncertain:1
Sep 28, 2023
Institute of Human Genetics, University Hospital Muenster
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

ACMG categories: - -

not specified Benign:1
Dec 21, 2017
GeneDx
Significance:Likely 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. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
BayesDel_noAF
Benign
-0.15
CADD
Uncertain
24
DANN
Uncertain
0.98
PhyloP100
4.9

Splicing

Name
Calibrated prediction
Score
Prediction
dbscSNV1_ADA
Benign
0.34
dbscSNV1_RF
Benign
0.44
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

Other links and lift over

dbSNP: rs200872349; hg19: chr20-62050967; API