chr9-135792134-C-T

Variant summary

Our verdict is Benign. The variant received -21 ACMG points: 0P and 21B. BP4_StrongBP6_Very_StrongBP7BS1BS2

The NM_020822.3(KCNT1):​c.3681C>T​(p.Pro1227Pro) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000123 in 1,605,900 control chromosomes in the GnomAD database, including 2 homozygotes. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Likely benign (★★).

Frequency

Genomes: 𝑓 0.00030 ( 0 hom., cov: 32)
Exomes 𝑓: 0.00010 ( 2 hom. )

Consequence

KCNT1
NM_020822.3 synonymous

Scores

2

Clinical Significance

Benign/Likely benign criteria provided, multiple submitters, no conflicts B:7

Conservation

PhyloP100: -1.83

Publications

0 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 -21 ACMG points.

BP4
Computational evidence support a benign effect (BayesDel_noAF=-0.78).
BP6
Variant 9-135792134-C-T is Benign according to our data. Variant chr9-135792134-C-T is described in ClinVar as Benign/Likely_benign. ClinVar VariationId is 391286.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
BP7
Synonymous conserved (PhyloP=-1.83 with no splicing effect.
BS1
Variant frequency is greater than expected in population eas. GnomAd4 allele frequency = 0.000302 (46/152300) while in subpopulation EAS AF = 0.00136 (7/5166). AF 95% confidence interval is 0.000635. There are 0 homozygotes in GnomAd4. There are 18 alleles in the male GnomAd4 subpopulation. Median coverage is 32. This position passed quality control check.
BS2
High AC in GnomAd4 at 46 AD gene.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
KCNT1NM_020822.3 linkc.3681C>T p.Pro1227Pro synonymous_variant Exon 31 of 31 ENST00000371757.7 NP_065873.2

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
KCNT1ENST00000371757.7 linkc.3681C>T p.Pro1227Pro synonymous_variant Exon 31 of 31 1 NM_020822.3 ENSP00000360822.2

Frequencies

GnomAD3 genomes
AF:
0.000302
AC:
46
AN:
152182
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.000820
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.000131
Gnomad ASJ
AF:
0.00
Gnomad EAS
AF:
0.00135
Gnomad SAS
AF:
0.000207
Gnomad FIN
AF:
0.0000941
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.0000147
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.000287
AC:
69
AN:
240822
AF XY:
0.000236
show subpopulations
Gnomad AFR exome
AF:
0.00134
Gnomad AMR exome
AF:
0.0000584
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.000988
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.000136
Gnomad OTH exome
AF:
0.000167
GnomAD4 exome
AF:
0.000105
AC:
152
AN:
1453600
Hom.:
2
Cov.:
32
AF XY:
0.000113
AC XY:
82
AN XY:
723390
show subpopulations
African (AFR)
AF:
0.00120
AC:
40
AN:
33448
American (AMR)
AF:
0.0000673
AC:
3
AN:
44598
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26072
East Asian (EAS)
AF:
0.000706
AC:
28
AN:
39650
South Asian (SAS)
AF:
0.000419
AC:
36
AN:
85994
European-Finnish (FIN)
AF:
0.0000216
AC:
1
AN:
46248
Middle Eastern (MID)
AF:
0.000347
AC:
2
AN:
5766
European-Non Finnish (NFE)
AF:
0.0000270
AC:
30
AN:
1111530
Other (OTH)
AF:
0.000199
AC:
12
AN:
60294
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.471
Heterozygous variant carriers
0
10
19
29
38
48
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Exome Hom
Variant carriers
0
4
8
12
16
20
<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:
0.000302
AC:
46
AN:
152300
Hom.:
0
Cov.:
32
AF XY:
0.000242
AC XY:
18
AN XY:
74460
show subpopulations
African (AFR)
AF:
0.000818
AC:
34
AN:
41574
American (AMR)
AF:
0.000131
AC:
2
AN:
15306
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3470
East Asian (EAS)
AF:
0.00136
AC:
7
AN:
5166
South Asian (SAS)
AF:
0.000208
AC:
1
AN:
4816
European-Finnish (FIN)
AF:
0.0000941
AC:
1
AN:
10626
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
294
European-Non Finnish (NFE)
AF:
0.0000147
AC:
1
AN:
68024
Other (OTH)
AF:
0.00
AC:
0
AN:
2112
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.502
Heterozygous variant carriers
0
3
6
8
11
14
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:
0.000395
Hom.:
0
Bravo
AF:
0.000567
Asia WGS
AF:
0.000577
AC:
2
AN:
3478
EpiCase
AF:
0.00
EpiControl
AF:
0.000119

ClinVar

Significance: Benign/Likely benign
Submissions summary: Benign:7
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Developmental and epileptic encephalopathy, 14;C3554306:Autosomal dominant nocturnal frontal lobe epilepsy 5 Benign:2
Jan 24, 2022
Fulgent Genetics, Fulgent Genetics
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Jan 13, 2025
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

not provided Benign:2
Mar 07, 2020
GeneDx
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Oct 25, 2024
ARUP Laboratories, Molecular Genetics and Genomics, ARUP Laboratories
Significance:Benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Inborn genetic diseases Benign:1
Jan 12, 2017
Ambry Genetics
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This alteration is classified as likely benign based on a combination of the following: seen in unaffected individuals, population frequency, intact protein function, lack of segregation with disease, co-occurrence, RNA analysis, in silico models, amino acid conservation, lack of disease association in case-control studies, and/or the mechanism of disease or impacted region is inconsistent with a known cause of pathogenicity. -

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

- -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
BayesDel_noAF
Benign
-0.78
CADD
Benign
0.060
DANN
Benign
0.87
PhyloP100
-1.8
Mutation Taster
=97/3
polymorphism

Splicing

Name
Calibrated prediction
Score
Prediction
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: rs149049198; hg19: chr9-138683980; API