9-135786170-CGCCCTGCCCTGCCCT-CGCCCTGCCCTGCCCTGCCCTGCCCT

Variant summary

Our verdict is Benign. The variant received -8 ACMG points: 8P and 16B. PVS1BP6_Very_StrongBS1BS2

The NM_020822.3(KCNT1):​c.3178-12_3178-3dupTGCCCTGCCC variant causes a splice acceptor, intron change involving the alteration of a non-conserved nucleotide. Variant has been reported in ClinVar as Likely benign (★★).

Frequency

Genomes: 𝑓 0.00052 ( 0 hom., cov: 0)
Exomes 𝑓: 0.00033 ( 2 hom. )

Consequence

KCNT1
NM_020822.3 splice_acceptor, intron

Scores

Not classified

Clinical Significance

Likely benign criteria provided, multiple submitters, no conflicts B:5

Conservation

PhyloP100: 0.600

Publications

1 publications found
Variant links:
Genes affected
KCNT1 (HGNC:18865): (potassium sodium-activated channel subfamily T member 1) Potassium channels represent the most complex class of voltage-gated ion channels from both functional and structural standpoints. Their diverse functions include regulating neurotransmitter release, heart rate, insulin secretion, neuronal excitability, epithelial electrolyte transport, smooth muscle contraction, and cell volume. This gene encodes a sodium-activated potassium channel subunit which is thought to function in ion conductance and developmental signaling pathways. Mutations in this gene cause the early-onset epileptic disorders, malignant migrating partial seizures of infancy and autosomal dominant nocturnal frontal lobe epilepsy. Alternative splicing results in multiple transcript variants. [provided by RefSeq, Dec 2012]
KCNT1 Gene-Disease associations (from GenCC):
  • childhood-onset epilepsy syndrome
    Inheritance: AD Classification: DEFINITIVE Submitted by: ClinGen
  • developmental and epileptic encephalopathy, 14
    Inheritance: AD Classification: DEFINITIVE, STRONG, MODERATE Submitted by: Labcorp Genetics (formerly Invitae), Ambry Genetics, G2P
  • malignant migrating partial seizures of infancy
    Inheritance: AD Classification: DEFINITIVE, SUPPORTIVE Submitted by: G2P, Orphanet
  • autosomal dominant nocturnal frontal lobe epilepsy 5
    Inheritance: AD Classification: STRONG, MODERATE Submitted by: Ambry Genetics, Labcorp Genetics (formerly Invitae)
  • autosomal dominant nocturnal frontal lobe epilepsy
    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 -8 ACMG points.

PVS1
Splicing +-2 bp (donor or acceptor) variant, LoF is a know mechanism of disease, No cryptic splice site detected. Exon removal results in frameshift change.
BP6
Variant 9-135786170-C-CGCCCTGCCCT is Benign according to our data. Variant chr9-135786170-C-CGCCCTGCCCT is described in ClinVar as Likely_benign. ClinVar VariationId is 421819.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
BS1
Variant frequency is greater than expected in population eas. GnomAd4 allele frequency = 0.000518 (78/150642) while in subpopulation EAS AF = 0.00118 (6/5068). AF 95% confidence interval is 0.00053. There are 0 homozygotes in GnomAd4. There are 34 alleles in the male GnomAd4 subpopulation. Median coverage is 0. This position passed quality control check.
BS2
High AC in GnomAd4 at 78 AD gene.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
KCNT1NM_020822.3 linkc.3178-12_3178-3dupTGCCCTGCCC splice_acceptor_variant, intron_variant Intron 28 of 30 ENST00000371757.7 NP_065873.2 Q5JUK3-3

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
KCNT1ENST00000371757.7 linkc.3178-12_3178-3dupTGCCCTGCCC splice_acceptor_variant, intron_variant Intron 28 of 30 1 NM_020822.3 ENSP00000360822.2 Q5JUK3-3

Frequencies

GnomAD3 genomes
AF:
0.000525
AC:
79
AN:
150528
Hom.:
0
Cov.:
0
show subpopulations
Gnomad AFR
AF:
0.000738
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.000395
Gnomad ASJ
AF:
0.000289
Gnomad EAS
AF:
0.00118
Gnomad SAS
AF:
0.000842
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00633
Gnomad NFE
AF:
0.000414
Gnomad OTH
AF:
0.000969
GnomAD2 exomes
AF:
0.000401
AC:
79
AN:
197052
AF XY:
0.000420
show subpopulations
Gnomad AFR exome
AF:
0.000388
Gnomad AMR exome
AF:
0.000293
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00104
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.000414
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.000331
AC:
462
AN:
1397630
Hom.:
2
Cov.:
12
AF XY:
0.000356
AC XY:
248
AN XY:
696464
show subpopulations
African (AFR)
AF:
0.000327
AC:
10
AN:
30558
American (AMR)
AF:
0.000360
AC:
14
AN:
38862
Ashkenazi Jewish (ASJ)
AF:
0.0000398
AC:
1
AN:
25146
East Asian (EAS)
AF:
0.000932
AC:
36
AN:
38610
South Asian (SAS)
AF:
0.000452
AC:
37
AN:
81936
European-Finnish (FIN)
AF:
0.0000198
AC:
1
AN:
50462
Middle Eastern (MID)
AF:
0.000536
AC:
3
AN:
5596
European-Non Finnish (NFE)
AF:
0.000315
AC:
337
AN:
1068466
Other (OTH)
AF:
0.000397
AC:
23
AN:
57994
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.411
Heterozygous variant carriers
0
21
41
62
82
103
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
10
20
30
40
50
<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:
0.000518
AC:
78
AN:
150642
Hom.:
0
Cov.:
0
AF XY:
0.000462
AC XY:
34
AN XY:
73586
show subpopulations
African (AFR)
AF:
0.000736
AC:
30
AN:
40752
American (AMR)
AF:
0.000394
AC:
6
AN:
15210
Ashkenazi Jewish (ASJ)
AF:
0.000289
AC:
1
AN:
3466
East Asian (EAS)
AF:
0.00118
AC:
6
AN:
5068
South Asian (SAS)
AF:
0.000843
AC:
4
AN:
4744
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10472
Middle Eastern (MID)
AF:
0.00680
AC:
2
AN:
294
European-Non Finnish (NFE)
AF:
0.000399
AC:
27
AN:
67648
Other (OTH)
AF:
0.000959
AC:
2
AN:
2086
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.507
Heterozygous variant carriers
0
5
10
14
19
24
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:
0.000313
Hom.:
365

ClinVar

Significance: Likely benign
Submissions summary: Benign:5
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

not specified Benign:2
Aug 01, 2018
Eurofins Ntd Llc (ga)
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

May 17, 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. -

KCNT1-related disorder Benign:1
Jul 28, 2020
PreventionGenetics, part of Exact Sciences
Significance:Likely benign
Review Status:no assertion criteria provided
Collection Method:clinical testing

This variant is classified as likely benign based on ACMG/AMP sequence variant interpretation guidelines (Richards et al. 2015 PMID: 25741868, with internal and published modifications). -

Developmental and epileptic encephalopathy, 14 Benign:1
Mar 15, 2022
Genome-Nilou Lab
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Autosomal dominant nocturnal frontal lobe epilepsy 5 Benign:1
Mar 15, 2022
Genome-Nilou Lab
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
PhyloP100
0.60
Mutation Taster
=100/0
polymorphism

Splicing

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

Other links and lift over

dbSNP: rs757968008; hg19: chr9-138678016; API