9-135768652-C-T

Variant summary

Our verdict is Benign. The variant received -9 ACMG points: 0P and 9B. BP4_ModerateBP6_ModerateBP7BS2

The NM_020822.3(KCNT1):​c.1380C>T​(p.Asn460Asn) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000645 in 1,550,426 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Likely benign (★).

Frequency

Genomes: 𝑓 0.000013 ( 0 hom., cov: 30)
Exomes 𝑓: 0.0000057 ( 0 hom. )

Consequence

KCNT1
NM_020822.3 synonymous

Scores

2

Clinical Significance

Likely benign criteria provided, single submitter B:2

Conservation

PhyloP100: -1.35

Publications

2 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 -9 ACMG points.

BP4
Computational evidence support a benign effect (BayesDel_noAF=-0.32).
BP6
Variant 9-135768652-C-T is Benign according to our data. Variant chr9-135768652-C-T is described in ClinVar as Likely_benign. ClinVar VariationId is 540586.Status of the report is criteria_provided_single_submitter, 1 stars.
BP7
Synonymous conserved (PhyloP=-1.35 with no splicing effect.
BS2
High AC in GnomAdExome4 at 8 AD gene.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
KCNT1NM_020822.3 linkc.1380C>T p.Asn460Asn synonymous_variant Exon 14 of 31 ENST00000371757.7 NP_065873.2 Q5JUK3-3

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
KCNT1ENST00000371757.7 linkc.1380C>T p.Asn460Asn synonymous_variant Exon 14 of 31 1 NM_020822.3 ENSP00000360822.2 Q5JUK3-3

Frequencies

GnomAD3 genomes
AF:
0.0000132
AC:
2
AN:
152030
Hom.:
0
Cov.:
30
show subpopulations
Gnomad AFR
AF:
0.0000483
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:
0.00
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.00
AC:
0
AN:
155898
AF XY:
0.00
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 FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.00
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.00000572
AC:
8
AN:
1398278
Hom.:
0
Cov.:
31
AF XY:
0.00000435
AC XY:
3
AN XY:
689680
show subpopulations
African (AFR)
AF:
0.0000633
AC:
2
AN:
31590
American (AMR)
AF:
0.00
AC:
0
AN:
35700
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
25168
East Asian (EAS)
AF:
0.00
AC:
0
AN:
35736
South Asian (SAS)
AF:
0.00
AC:
0
AN:
79222
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
48368
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5674
European-Non Finnish (NFE)
AF:
0.00000463
AC:
5
AN:
1078836
Other (OTH)
AF:
0.0000172
AC:
1
AN:
57984
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.419
Heterozygous variant carriers
0
1
2
3
4
5
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:
0.0000131
AC:
2
AN:
152148
Hom.:
0
Cov.:
30
AF XY:
0.0000134
AC XY:
1
AN XY:
74382
show subpopulations
African (AFR)
AF:
0.0000482
AC:
2
AN:
41510
American (AMR)
AF:
0.00
AC:
0
AN:
15302
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3470
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5126
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4814
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10616
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
294
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
67992
Other (OTH)
AF:
0.00
AC:
0
AN:
2112
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.575
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance
Alfa
AF:
0.0000712
Hom.:
0
Bravo
AF:
0.00000756

ClinVar

Significance: Likely benign
Submissions summary: Benign:2
Revision: criteria provided, single submitter
LINK: link

Submissions by phenotype

Developmental and epileptic encephalopathy, 14;C3554306:Autosomal dominant nocturnal frontal lobe epilepsy 5 Benign:1
Jun 11, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

KCNT1-related disorder Benign:1
Jul 31, 2019
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). -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
BayesDel_noAF
Benign
-0.32
CADD
Benign
11
DANN
Benign
0.91
PhyloP100
-1.4

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.020
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: rs566700584; hg19: chr9-138660498; API